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Here is presented a room disinfection device based in Ultraviolet-C radiation. Initially, it was designed for the periodic conditioning of culture rooms. It offers the capacity to be remotely programmed using an Android mobile device and it has an infrared detection security system that turns off the system when triggered. The system here described is easily scalable to generate higher ultraviolet dosages adding more UV-C lamps. The experimental tests showed the very high effectiveness of this device to eliminate high bacterial inocula. The sanitizing method employed by this device affects a very wide range of microorganisms and it has several advantages respect to chemical based-sanitizing methods. The total cost to make this open source device is below USD 180 and it is easily customizable which is different respect to proprietary commercial devices actually available. This device represents an open source, secure, fast and automatized equipment for room disinfecting. The device is configured in less than three minutes and it does not require continuous monitoring.
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Programmable and low-cost ultraviolet room disinfection
Marcel Bentancor
, Sabina Vidal
Laboratorio de Biología Molecular Vegetal, Facultad de Ciencias, Universidad de la Republica, Iguá 4225, Montevideo, Uruguay
article info
Article history:
Received 2 June 2018
Received in revised form 19 October 2018
Accepted 30 October 2018
Here is presented a room disinfection device based in Ultraviolet-C radiation. Initially, it
was designed for the periodic conditioning of culture rooms. It offers the capacity to be
remotely programmed using an Android mobile device and it has an infrared detection
security system that turns off the system when triggered. The system here described is
easily scalable to generate higher ultraviolet dosages adding more UV-C lamps. The exper-
imental tests showed the very high effectiveness of this device to eliminate high bacterial
inocula. The sanitizing method employed by this device affects a very wide range of
microorganisms and it has several advantages respect to chemical based-sanitizing meth-
ods. The total cost to make this open source device is below USD 180 and it is easily
customizable which is different respect to proprietary commercial devices actually avail-
able. This device represents an open source, secure, fast and automatized equipment for
room disinfecting. The device is configured in less than three minutes and it does not
require continuous monitoring.
Ó2018 The Authors. Published by Elsevier Ltd. This is an open access article under the CC BY
license (
Specifications table
Hardware name Programmable and low-cost ultraviolet room disinfection device.
Subject area Biological Sciences (e.g. Microbiology and Biochemistry)
Educational Tools and Open Source Alternatives to Existing Infrastructure
Hardware type Biological sample handling and preparation
Other [culture room disinfection]
Open Source License Creative Commons Attribution-ShareAlike 4.0 International License.
Cost of Hardware USD 176.40
Source File Repository
1. Hardware in context
Since the last years, mobiles systems based on UV-C radiation have been used for cleaning and disinfecting hospitals
[1–4]. The contribution of this equipment to the conditioning of hospital areas makes these systems useful for other kinds
of spaces that require periodical disinfecting. The spaces which require control of the presence of microorganisms need effec-
tive, fast and economical controls, and also, that can be used on a frequent basis. When the growth of microorganisms is not
2468-0672/Ó2018 The Authors. Published by Elsevier Ltd.
This is an open access article under the CC BY license (
Corresponding author.
E-mail address: (M. Bentancor).
HardwareX 4 (2018) e00046
Contents lists available at ScienceDirect
journal homepage:
under control, they can interfere with the experiments carried in such spaces. For example, our group has several plant cul-
ture rooms designated to provide optimal conditions for plant growth. However, these conditions tend to promote contam-
inations with unwanted microorganisms, such as bacteria and fungi, that once established, are very difficult to eradicate. To
avoid or minimize the use of chemical agents, potentially aggressive to the surfaces of culture rooms and to minimize the
impact on the environment that can result from these agents, our group has chosen to include in the work routine, a peri-
odical irradiation of the culture rooms with UV-C, in order to eliminate and prevent biological contaminants. This practice
has been effective and requires less personal than the manual cleaning and disinfection based on chemical agents. UV-C radi-
ation inactivates microorganisms causing DNA damage by producing cyclobutane pyrimidine dimers (CPDs), altering DNA
structure, and thus interfering with DNA replication [5,6]. According to the World Health Organization Global Solar UV Index,
the UV region covers the wavelength range from 100 to 400 nm and is divided into three bands: UV-A (315–400 nm) UV-B
(280–315 nm) and UV-C (100–280 nm). Depending on its wavelength, intensity, and method of application, there are differ-
ent applications of ultraviolet light, for example, tanning, phototherapy, curing of materials, studies of UV aging for acceler-
ated weathering of materials, technical inspections using the luminescence or fluorescence induced by UV light, and
disinfection [7]. UV-C light, which is absorbed by the atmosphere, represents the most lethal wavelength for a wide spec-
trum of microorganisms. The maximum germicidal power of the ultraviolet radiation is at wavelengths near 260 nm and
it drops dramatically below 230 or above 300 nm. The ultraviolet light was discovered in 1801 and since the discovery of
the germicidal effect of this radiation in 1878 [8] it prompted its application for the microbial control. As early as 1903,
the UV-C germicidal effect was the basis for Niels Finsen to achieve the Nobel Prize of Medicine [9] and until today new
forms are being invented to apply this radiation for microorganism control [10–12].
In addition to UV-C irradiation, other methods of disinfection for large areas include the use of gaseous agents (formalde-
hyde, ethylene oxide, etc.) which are hazardous and require an air flow pattern. Likewise, liquid agents, such as sodium
hypochlorite are also employed for disinfection purposes, but these must be carefully removed after being applied and
may damage exposed materials (for example, electronic devices). Other methods include the use of ionizing radiation, but
in addition to being hazardous, they require very specialized equipment [13]. Although since mid-20th century UV treat-
ments have been used for disinfection (reviewed in [14]), only in recent years this technology became more reliable as a con-
sequence of the incremented lifespan of UV lamps. the use of UV-C is a chemical free and low-cost procedure, which
represents a green alternative method for disinfection.
2. Hardware description
The use of commercial proprietary equipment for UV-C radiation of the environment entails a significant cost to acquire
the equipment and to repair it because it has a proprietary technology. Most of the available equipment use low-pressure
mercury lamps to produce UV-C radiation. These lamps can be acquired separately and used in the open source device
described here. We have constructed a UV-C radiator device that includes a microcontroller board, an Arduino UNO board
[15]. This microcontroller board is used to operate the system and permits the establishment of security measures which
are frequently restricted to the most expensive property models [16]. In addition, the equipment can be operated from a
wide range of Android mobile devices with suitable screens and processing capacity (tablet, cell phone, etc), taking advan-
tage of the ubiquity of these devices, and lowering the cost of its construction.
Some of the uses that can be given to this device are:
Culture room disinfection.
Material curing.
Lowering the microbial load in food supplies (example: vegetables).
3. Design files
Design file name File type Open source license Location of the file
Design file 1 APK file Creative Commons Attribution-
ShareAlike 4.0 International License.
Design file 2 AIA file Creative Commons Attribution-
ShareAlike 4.0 International License.
Design file 3 MP4 file Creative Commons Attribution-
ShareAlike 4.0 International License.
Design file 4 INO file Creative Commons Attribution-
ShareAlike 4.0 International License.
Design file 1, is the APK file for the Android app which commands the device.
Design file 2, contains the source code for the app which commands the device.
Design file 3, contains a video showing the operation of the device.
Design file 4, contains the source code to program the Arduino UNO board of the device.
2M. Bentancor, S. Vidal /HardwareX 4 (2018) e00046
4. Bill of materials
The full bill of materials is shown in Table 1. The main components of the device and the fully assembled device are
shown in Fig. 1.
Table 1
Full bill of materials required to make the UV-C device.
Component Number Cost per
unit -USD
Total cost
Source of materials Material type
Arduino UNO board 1 8.49 8.49
Bluetooth module HC06 1 6.99 6.99
PIR sensor 1 6.99 6.99
Relay module (5 V) 1 5.80 5.80
LEDs 3 0.40 1.20
Resistors (100
) 3 0.01 0.03
Passive buzzer 1 0.50 0.50
Double Sided PCB Board
Prototype (8 cm 2 cm)
1 0.40 0.40
UV-C lamp (Phillips TUV-T8
30 W) with holder
420 80
Holder or light fixture for
the UV-C lamps
45 20
220 V/5V, 1A electric
1 7 7 Local hardware store Electronic
Plastic box
(15 cm 12 cm 7 cm)
1 5 5 Local hardware store Plastic
Wheels 4 2 8 Local hardware store Metal and plastic
Wooden column
(98 cm 10 cm)
1 5 5 Local hardware store Wood
Wooden base
(56 cm 46 cm 2 cm)
1 4 4 Local hardware store Wood
Wires 4m 1 4 Local hardware store Other
Connection strip 1 1 1 Local hardware store Metal and plastic
Female AC power plug 1 3 3 Local hardware store Metal and plastic
Male AC power plug 2 3 6 Local hardware store Metal and plastic
Metal ring (30 cm 20 cm) 1 3 3 Local hardware store Metal
Total cost: USD 176.40.
M. Bentancor, S. Vidal /HardwareX 4 (2018) e00046 3
5. Build instructions
The construction of the device involved three stages: structural building, electronic assembling, and programming of the
microcontroller and the mobile application. The scaffold structure was made by attaching to a central column four holders
for UV-C germicide lamps (Phillips, model TUV T8), connected in parallel. The central column was placed on a mobile base,
and on its upper end, a metallic ring was attached to allow easy driving of the device and to bring support for the control
unit. In this way, the ring is connected to the bottom mobile base through a solid wooden column, which is strong enough
to tolerate the necessary push to move the device. A schematic view of the assembled model is shown in Fig. 2. The four UV-C
Fig. 2. Schematic view of the UV-C room disinfecting device. a) Assembling guide. The central column (1) was fixed using four screws. (2). In the lower part
of this base, four rotating wheels were placed (3). Four holder lamps (4) were attached around the central column (1) using screws. The four lamps were
wired, guiding its wires through the control unit (6) which was installed inside the supporting metal ring (5) which was fixed on the upper part on the
central column. Different views of the device are shown: front view (b) side view (c) and perspective view (d).
Fig. 1. UV-C room disinfection device assembled, main components are indicated.
4M. Bentancor, S. Vidal /HardwareX 4 (2018) e00046
lamps were connected in parallel between them. The supply wire was connected to the control unit using a male plug. The
control unit was placed on the upper part of the device.
The control unit is based on an Arduino UNO board; this gives the order to the switch to turn on the UV-C lamps using an
electromechanical relay. An HCO6 Bluetooth module is used to communicate with the board using Bluetooth devices. Three
LEDs were installed to indicate it functional estate:
Connected to the electric supply (green LED)
Bluetooth connection established (blue LED)
UV-C lamps activated (red LED)
The red LED is combined with a passive buzzer to start a warning sequence just before the activation of the UV-C lamps. In
this way, the user is warned about the imminent switching on of the UV-C lamps. To emphasize this critical warning, a char-
acteristic sequence combining flashing of the red LED and sound from the buzzer was included in the code for the Arduino
Because the UV-C radiation is harmful to humans, a PIR sensor was added as a security measure. In this way, the device is
automatically turned off when a user is near. When the PIR detects a moving warm body turns off the UV-C lamps. To reac-
tivate the lamps, the device requires the intervention of the user. This PIR sensor brings a conical coverage encompassing 110
degrees towards the front part. The device needs to be oriented toward the entry door of the room which is desired to irra-
diate. Eventually, it is possible to add more PIR sensors to increase the infrared coverage of the device.
The electrical powering of the device is through the electrical network (AC 220v) which provides energy for the UV-C
lamps and feeds the Arduino board and the rest of the electronic circuit through a USB adapter (5 V). The electrical diagram
of the connections is shown in Fig. 3. The source code for the Arduino board is provided in Appendix A. The relay controls one
of the conductors used to energize the UV-C lamps. External and internal views of the control unit are shown in Fig. 4.
Finally, a mobile application was developed to control the disinfecting unit. This app was designed using the MIT app
inventor 2 tool [17]. The interface of this application is used for connection to the device via Bluetooth, and for selecting
the irradiation time. The radiation time can be set using a drop menu or allowing the manual introduction of the time lapse.
The application shows the running timer during the irradiation period. Since switching on and off of the UV lamps depend on
the Android device commands, during these moments the Android device must remain connected to the UV-C device via
Bluetooth. In the main screen of the application is possible to consult reference values of UV-C dosages required to eliminate
the 99.9% of different inoculums according to publically available data [18,19]. A more extensive list of UV-C dosages is pos-
sible to obtain in the provided references. Characteristic sounds and alerts were added to the app to indicate switching on or
off the UV-C lamps.
Detailed build instructions. Tools list provided to each sub-heading
Fig. 3. Wiring diagram. Except for the UV-C lamps, all the components were assembled inside the plastic box of the control unit. R1, R2, and R3 are resistors
). Relevant connections are labeled.
M. Bentancor, S. Vidal /HardwareX 4 (2018) e00046 5
5.1. Mobile base and main structure
Phillips screwdriver, plier drill
Four gyratory wheels were fixed using screws to a wooden table (56 cm 46 cm). At the center of the table, a wooden
column was attached using four screws. In an equidistant way, four lamp holders were attached around the central wooden
column employing screws. These holders were wired appropriately to connect in parallel the four lamps. The power supply
for the lamps was attached to the column and it was connected in one extreme to a female plug to facilitate subsequent con-
nection to the control unit. To the upper part of the column, a metal ring was attached using screws. The function of this s
ring is to support the control unit and to facilitate the transport of the UV-C device.
5.2. Control unit
Soldering iron, hot glue gun, plier, Phillips screwdriver, electric drill, and conic drill
The LEDs, resistors, and buzzer were mounted over the surface of the double-sided PCB board prototype according to the
wiring diagram depicted in Fig. 3. Circuits tracks were traced using the iron soldering. This PCB board was attached, using hot
glue, inside the plastic box of the unit control, and three holes were made in such a way that the three LEDs emerged outside
the control unit. A hole was made in the door of the plastic box, using the conic drill, to locate the sensor of the PIR module. In
one of the sides of the plastic box, the Bluetooth module was attached using hot glue, and the relay module was attached
using screws. The Arduino UNO board was attached inside the plastic box using Phillips screws. All connections were made
using cables according to the connection depicted in Fig. 3.
The supply cord was assembled installing a male plug in one extreme, for plugging into a regular electric wall socket. The
other extreme of the cord was introduced into the plastic box of the unit control through a hole made with the drill. This cord
was bifurcated using a connecting strip, from which the following connections were made: 1) the UV-C lamps were con-
nected directly to one of the poles, the other pole was connected directly to the lamps but through the relay module, using
the output labeled in the module ‘‘normally open”. 2) Using a second connecting strip, the 220 V/5V power adapter was con-
nected to the Arduino board through a USB cable. The rest of the electronic components of the control unit were energized by
the Arduino board according to the wiring diagram showed in Fig. 3. The assembled control unit is showed in Fig. 4. By open-
ing the control unit and disconnecting the USB from the 220 V/5V adapter it is possible to connect a computer to load the
script on the Arduino board. Before loading the script, it is necessary to disconnect the TXD and RXD terminals from the Blue-
tooth module. After loading the script, both terminals need to be reconnected, and the USB cable reconnected to the electric
adapter. After this, the unit control door is closed and the device is ready to work.
Fig. 4. Control unit of the UV-C room disinfection device. External view (left). Internal view (right). 1, a plug for connect to the UV-C lamps. 2, Power supply
cord. 3, LED to indicate the connection to the electric supply. 4, LED to indicate an established Bluetooth connection. 5, LED to indicate the lighting of the
lamps. 6, buzzer and PCB board for connections of the components. 7, relay module. 8, Arduino UNO board. 9, the output for the power supply cord for the
UV-C lamps. 10 and 12, electrical connections using connection strips. 11, power adapter (220 V/5V) to energize the Arduino board and associated modules.
13, PIR sensor.
6M. Bentancor, S. Vidal /HardwareX 4 (2018) e00046
6. Operation instructions
1) Install the app ‘‘UVC disinfection device” in your android mobile device. Previously, the Android device has to be
enabled to install apps from unknown sources. Plug the UVC disinfecting device to the electrical network. The green
LED will turn on
2) Execute the app previously installed on your mobile device.
3) Connect to the UVC disinfecting device by Bluetooth. Once the connection is established, the blue LED will turn on.
4) Select the radiation time, you can manually set the time or choose it from the drop menu.
5) Click on the ‘‘Activate” button. The app shows the estate of the UVC device as ‘‘Activated”. The red LED will turn on and
start blinking. This light will be accompanied by the sound of the buzzer emitting several short beeps. After the last
longer beep, the UVC lamps will turn on. The red LED will switch from blinking to continuous and will stay on as long
as the UVC lamps are functioning.
6) The app will switch off the device upon completion of the programmed time. The app will show the estate of the
device as ‘‘Inactivated” and the red light will turn off. Alternatively, the device may be switched off by clicking on
the ‘‘stop” button. The timer may be reset by clicking on the ‘‘reset” button.
7) The dosage reference table shows some reference values for UVC dosage required to disinfect up to 99.9% of different
kind of microorganisms.
8) Exit the app by clicking on the ‘‘Exit” button. The blue LED will turn off.
The main use of this sanitizer is to reduce or eliminate a wide range of microorganisms existing in a specific area. The
reference values for dosage are provided to allow the user estimation of the minimum exposure time that needs to be used.
These values are only indicative, and therefore, the optimal exposure time should be determined experimentally according
to the needs. The dosages values indicated in reference [13] can be used to estimate the required exposure time according to
the following simplified method:
The UV-C dosage received by surface unit (D, expressed in J/cm
) at a given distance (r) from the sanitizer, depends on the
power of the emitted UV-C light (P, equal to 48 W for our device) according to this equation:
:L:rÞ ð1Þ
where L is the length of the UV-C lamps (89 cm) and t is the exposure time expressed in seconds.
Based on this equation, the exposure time can be calculated as follows:
Using this method, a tool to estimate the minimum exposure time to reach the desired dosage for a certain distance from
the device (Fig. 5b) was developed and is available in the initial screen of the app controlling the device.
Fig. 5. Capture screens of the developed app for the UVC disinfecting device. a) Splash screen b) Tool for estimate the exposure time. c) Main screen.
M. Bentancor, S. Vidal /HardwareX 4 (2018) e00046 7
7. Validation and characterization
The dimensions of the device are 50 45 130 cm (width depth height). The bottom base has four wheels to facil-
itate movement. Fig. 6 shows the UV-C device in operating mode. A video of the operating device is provided as supplemen-
tary material. Any part of the environment which is illuminated by the device directly receives UV-C radiation. It is
recommended to irradiate the room using the device in different successive positions. The use of this device does not replace
other methods for disinfection but contributes with an additional measure for the destruction of airborne organisms or inac-
tivation of microorganisms on surfaces.
In order to evaluate the effectiveness of the UV-C device, Petri dishes with a known inoculum of Escherichia coli strain K12
W3110 were irradiated. Under the tested conditions it was possible to almost eliminate all bacteria in the cultures. In a first
assay, a Petri dish with a non-selective medium, low salt Luria-Bertani (composition: 5 g/L sodium chloride, 5 g/L yeast
extract, 10 g/L tryptone, 15 g/L agar) were inoculated with 200 mL of liquid culture of E. coli (1,9 E
colony forming units/
mL). These plates were placed vertically and open, one meter away from the UV-C device. One half of the plate was covered
by aluminum foil. After one hour of exposure to the device, the plates were closed and incubated overnight at 37 °C. Fig. 7
Fig. 6. UV-C device working. A video showing the setting up of the device is included in the supplementary material.
Fig. 7. Petri dishes inoculated with 200 mL of a liquid culture of E. coli strain K12 W3110 (1,9 E
CFU/mL) were irradiated during one hour at one meter from
the UV-C device. The right half of the plates were kept covered with aluminum foil during this period, while the left half of plate was kept discovered.
Duplicates of the experiment are shown, after being incubated the irradiated plates at 37 °C overnight.
8M. Bentancor, S. Vidal /HardwareX 4 (2018) e00046
clearly only shows bacterial growth in the zone of the plate that was not exposed to the UV-C rays (covered by aluminum
foil), while no growth was observed in the exposed side of the plates. These results show that the UV-C device was able to do
fully eliminate bacterial growth in an inoculum of 10
bacteria when plates were irradiated for one hour from a distance of
one meter.
In another test, plates inoculated with E. coli K12 W3110 were placed open and vertically at one meter and two meters
from the UV-C device, and after one-hour irradiation, they were closed and incubated overnight at 37 °C together with a non-
irradiated Petri dishes inoculated likewise. Fig. 8 shows that the device was able to completely kill the bacteria in the irra-
diated plates also when the procedure was done at a distance of two meters
To evaluate the required exposure time to kill the bacteria, low salt Luria-Bertani Petri dishes inoculated with 10
E. coli
K12 W3110 were placed at one meter from the device and withdrawn at 15-minute intervals for one hour. This experiment
shows that a 15 min exposure is enough to eliminate the inoculum (Fig. 9).
7.1. Cost analysis
Actually, the proprietary market offers disinfecting units based in UV-C lamps that use mercury or xenon. The first ones
are the most common and less expensive, and this kind of lamp is used in the device here presented. The required materials
Fig. 8. Effect of exposure to the disinfectant device on plates inoculated with 200 mL of a liquid culture of E. coli K12 W3110 (1,2 E
CFU/mL) placed at 1 m
and 2 m from the device and exposed during one hour. Duplicates of the experiment are shown.
Fig. 9. Effect of different times of UV-C exposure over plates inoculated with 200 mLofE. coli K12 W3110 liquid culture (1,9 E
CFU/mL) placed at one meter
from the UV-C device. Triplicates of the experiment are showed.
M. Bentancor, S. Vidal /HardwareX 4 (2018) e00046 9
to make this open source device are easily available locally and its cost, below USD 180, turns this in a very competitive
device because it represents a more than 80% save compared with proprietary commercial devices with similar functions
(see Table 2). If xenon lamps based devices are considered, the saved amount is even higher. These savings are in the order
of other reported savings for other kinds of open source hardware [20].
In this cost analysis the labor cost for the assembly of the device is not considered, however, and in the same way that for
other open source hardware [20] after being developed the prototype unit, this device can be replicated by any person with
basic knowledge about electronics. So this device is not only easily accessible to many laboratories that require room UV-C
disinfection but also can be used for training purposes on the use of this kind of microcontroller or the assembly of open
source hardware.
7.2. Perspectives and discussion
The development of this low-cost open source hardware expands access to this kind of equipment to be used in health-
care facilities, culture rooms, or any other environments that need to be periodically disinfected. Furthermore, this device is
useful for training human resources in building this device thus enabling the easy repairment of the equipment. Moreover,
because the know-how for structure building and programming of the hardware is provided here, this gives the opportunity
to the users to improve this equipment or scale it up to build higher power models if it is necessary. A possible improvement
maybe adding a time use register of the lamps. According to the lamp manufacturer, these have a useful life of 9.000 h,
whereafter such time, a 10% lumen depreciation is observed. This could be done by registering the use time in the EPROM
memory of the Arduino board, then.
Furthermore, the UV-C device could be constructed having more than four UV-C lamps, in case that it is found necessary. The
presented design easily allows its modification to include multiple circuits to operate all or a subset of lamps simultaneously.
The UV-C lamps model (Phillips, TUV T8) was chosen because according to the maker it has a special glass which filters
out the 185 nm ozone-forming radiation [21]. However, a post-irradiation time period or aeration is suggested to avoid
exposure to ozone in the newly disinfected room.
Because the UV-C apparatus is controlled by an Android mobile device using a Bluetooth connection, it is possible to
extend to a greater operational range, using Wi-Fi to connect to the mobile device, which in turn, controls the UVC apparatus.
In our lab, the UV-C apparatus is controlled via Bluetooth using an Android Tablet. In addition, we use the app Teamviewer
[22] to remotely connect to the tablet via Wi-Fi, and through this, operate the UV-C room disinfection device.
In our case, the UV-C device is used to disinfect plant culture rooms, the device is located near the middle of the room,
where the distance to the walls is 1.5 m. The UV-C dosage delivered by this device has been effective to disinfect these rooms
and is in the range of the required intensity, the four UVC lamps have 48 W as total UV-C output power.
8. Conclusions
An open source UV-C room disinfection device was made with similar functions to proprietary commercial systems. The
presented model can be easily scaled up, modifying its structure (adding more UV-C lamps) and programming (editing the
open source code of the Arduino board and/or of the Android application), achieving savings for more than 80% respect to the
price of similar proprietary commercial equipment.
Declarations of interest
The authors acknowledge to Mr. Luis Eduardo Casas the assembly of the structural support of the UV-C device. We
acknowledge Dr. Magela Laviña and her group for providing the bacterium E. coli K12 W3110 strain.
Table 2
Comparative prices of UV-C room sanitizers according to information provided by its sellers.
Model Manufacturer Source Price (USD)
GermAwayUV mobile CureUV
UV CARE room sterilizer UV CARE 1.850
MRS33-88 American Ultraviolet
MRS45-12 American Ultraviolet
10 M. Bentancor, S. Vidal /HardwareX 4 (2018) e00046
Appendix. -A code for Arduino board.
M. Bentancor, S. Vidal /HardwareX 4 (2018) e00046 11
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M. Bentancor, S. Vidal /HardwareX 4 (2018) e00046 13
... Similar vapors and gases applied in closed systems can provide excellent disinfection. Aerosols of hydrogen peroxide, chlorine dioxide, glutaraldehyde, paraformaldehyde, ethylene oxide, and peracetic acid are used in some laboratories to decontaminate biosafety cabinets or incubators [98,99]. However, all these chemicals are hazardous and disinfection with these substances should only be conducted by experienced and trained personnel. ...
... Finally, exposure to ultraviolet (UV) radiation can effectively destroy most microorganisms. In particular, the UV-C light (spectral range: 100-280 nm), which is absorbed by the atmosphere, has the most destructive power for a wide spectrum of microorganisms [99]. Therefore, this UV region is often used in biological safety cabinets to reduce surface contamination [98]. ...
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The cultivation of cells in a favorable artificial environment has become a versatile tool in cellular and molecular biology. Cultured primary cells and continuous cell lines are indispensable in investigations of basic, biomedical, and translation research. However, despite their important role, cell lines are frequently misidentified or contaminated by other cells, bacteria, fungi, yeast, viruses, or chemicals. In addition, handling and manipulating of cells is associated with specific biological and chemical hazards requiring special safeguards such as biosafety cabinets, enclosed containers, and other specialized protective equipment to minimize the risk of exposure to hazardous materials and to guarantee aseptic work conditions. This review provides a brief introduction about the most common problems encountered in cell culture laboratories and some guidelines on preventing or tackling respective problems.
... The following equation can be used to determine the system's Exposure Duration, which is measured in seconds [26]: ...
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Magnetic polymer composites have recently attracted considerable interest, primarily because of their promising applications, especially in the biomedical industry. The aim of this study is to investigate the impact of ultraviolet C (UVC) irradiation as a disinfection method on the mechanical characteristics of composite polymer magnets. Tensile and compression tests were conducted following the standards set by ASTM D3039 and ASTM D3410, respectively. In addition, energy dispersive spectroscopy (EDS) was used to determine the effect of the disinfection method on the amount of carbon, oxygen, and iron within the surface of the composite polymer magnet material. The UVC’s irradiation impact was statistically assessed by a t-test. The results of the tensile tests demonstrated a significant increase in the transition force, measuring 0.41 kN and 0.58 kN before and after UVC exposure, respectively. Similarly, the outcomes of the compression tests showed a notable increase in yield force, registering 4.9 kN and 6 kN before and after UVC treatment. This suggests that the composite magnetic material has gained a higher capacity to withstand compressive loads than tensile loads. Finally, the EDS analysis revealed the carbon mass percentage was 71.69% prior to UVC radiation exposure, with it increasing to 78.56%, following exposure. This suggests that the composite material exhibited improved hardness. These findings highlight that UVC irradiation has a beneficial impact on both the mechanical and chemical properties of the composite magnet material, which support its use as a disinfection method in clinical settings.
... However, there are various factors that affect the germicidal effectiveness of UV radiation, and its application requires careful consideration of the specific conditions in which it is used. In this paper, we review the literature on the use of UV radiation for germicidal purposes, examining its effectiveness, mechanisms of action, and potential applications in various settings Bentancor & Vidal (2018), Chanprakon et al. (2019). ...
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The COVID-19 pandemic has brought attention to the importance of keeping our surroundings clean and disinfected to mitigate the risk of contracting and spreading the virus. The use of ultraviolet (UV-C) radiation has been proven effective in disinfecting air, water, and surfaces, including reducing SARS-CoV-2 virus infectivity on surfaces to below detectable levels. However, limitations exist in the effectiveness of UVC radiation in inactivating viruses, particularly if the virus is not directly exposed to the radiation. This paper proposes a smart electronics system powered by an Arduino to design a 360-degree disinfection device using ultraviolet sterilization to solve the issue. The system aims to sterilize various items and surfaces to prevent the spread of COVID-19 and other germs.
... The media in each plate were divided into two regions, and each region was inoculated with the same species of microorganism tested. The half plate was then covered with aluminum foil, and the other half plate was left open [18]. The Petri were exposed to commercial UV-C light with exposure distances of 1 and 2 meters for 60 minutes. ...
... UV-C radiation is considered best for germicidal activity and is used to treat bacterial contamination [24]. In the previous study, the effectiveness of UV-C irradiation was demonstrated over S. aureus and P. aeruginosa when the light source was kept at a maximum distance of 2 cm, away facing directly over the samples at the center. ...
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Ultraviolet-C (UVC) sourced has been widely used for the purpose of disinfection due to its germicidal spectrum. In this study, the effectiveness of Everlight’s 275 nm Ultraviolet-C surface mounted device (UVC-SMD) to disinfect Staphylococcus aureus (S. aureus) was investigated at three exposure durations (10, 30 and 60 s) for a standard distance of 5 cm. The inhibition zones were greater with the increment of exposure duration. The highest records of 4.53 ± 0.03 cm were achieved when 102 mJ/cm² of dose was applied at a distance of 5 cm for 60 s. Whereas, on the other side, the lowest inhibition was seen when the exposure was set for 10 s. Thus, the Everlight 6565 UVC-SMD with 275 nm of wavelength is capable in providing bacterial disinfection which could possibly be used for the development of disinfection system based on SMDs at longer exposure duration.
... Bentancor and Vidal [39] have proposed a robot controlled remotely via mobile devices using the Android operating system and is equipped with a light-off system when detected human approaching. Using 4 UV-C lamps with a total power of 48W, the robot showed good bactericidal results against E.coli bacteria. ...
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Ultraviolet Germicidal Irradiation (UVGI) has grown significantly as an optimistic alternative to chemical disinfection for surface and air disinfection in the healthcare sector. The application of UVGI in robotic technology has led to new opportunities in developing the disinfection robot which allows us to prevent pathogen transmission, reduce human participation and cross infection, then achieve efficient, quick and environmentally friendly sterilization. The aim of this paper is to review the outstanding achievements in UV-C disinfection robot sector. This review is based on the reports on 35 types of UV-C disinfection robots in both academic research and commercial sector. The current and future trends in the UV-C lamp technologies and the technical capacities of the robot are also discussed.
Quantification of bacterial colonies on an agar plate is a daily routine for a microbiologist to determine the number of viable microorganisms in the sample. In general, microbiologists perform a visual assessment of bacterial colonies which is time-consuming (takes 2 min per plate), tedious, and subjective. Some automatic counting algorithms are developed that save labour and time, but their results are affected by the non-illumination on an agar plate. To improve this, the present manuscript aims to develop an inexpensive and efficient device to acquire S.aureus images via an automatic counting method using image processing techniques under real laboratory conditions. The proposed method (P_ColonyCount) includes the region of interest extraction and color space transformation followed by filtering, thresholding, morphological operation, distance transform, and watershed technique for the quantification of isolated and overlapping colonies. The present work also shows a comparative study on grayscale, K, and green channels by applying different filter and thresholding techniques on 42 images. The results of all channels were compared with the score provided by the expert (manual count). Out of all the proposed method (P_ColonyCount), the K channel gives the best outcome in comparison with the other two channels (grayscale and green) in terms of precision, recall, and F-measure which are 0.99, 0.99, and 0.99 (2 h), 0.98, 0.99, and 0.98 (4 h), and 0.98, 0.98, 0.98 (6 h) respectively. The execution time of the manual and the proposed method (P_ColonyCount) for 42 images ranges from 19 to 113 s and 15 to 31 s respectively. Apart from this, a user-friendly graphical user interface is also developed for the convenient enumeration of colonies without any expert knowledge/training. The developed imaging device will be useful for researchers and teaching lab settings.
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Performance optimization using process parameters of an indoor air filtration system is a requirement that has to be established through experimental and analytical means for increasing machine efficacy. A closed casing containing a motor-driven blower is placed in a glass-encapsulated control volume. Air flows axially through an inlet filter and is thrown radially by the blower. In the radial path, air is treated with free radicals from the UVC-irradiated nano-TiO2 coated in the inner wall of casing. A known quantity of Staphylococcus aureus bacteria is populated (Courtesy: EFRAC Laboratories) in the glass-encapsulated control volume. The bacterial colony count is measured at different time intervals after the machine is switched on. Machine learning approaches are applied to develop a hypothesis space and the hypothesis based on best R² score is used as a fitness function in genetic algorithm to find the optimal values of input parameters. The present research aims to determine the optimum time for which the setup is operated, the optimum air flow velocity in the chamber, the optimum setup-chamber-turning-radius affecting the air flow chaos, and the optimum UVC tube wattage, which when maintained yields the maximum reduction in bacterial colony count. The optimal values of the process parameters were obtained from genetic algorithm using the hypothesis obtained from multivariate polynomial regression. A reduction of 91.41% in bacterial colony count was observed in the confirmation run upon running the air filter in the optimal condition.
The authors demonstrate the enhanced light output from 275-nm AlGaN-based deep ultraviolet (DUV) light-emitting diode (LED) structures via the in-plane modulation of shallow photonic crystal (PC) patterns that were fabricated on the p-AlGaN contact layer surface. The employed PC lattice constants are in the range of 270–780 nm, much larger than the fundamental Bragg order lattice constant (∼95 nm). As compared to the unpatterned sample, the intensity of the top (or bottom) emission can be enhanced by up to 331% (or 246%), attributed to the high-order coherent diffraction of the internal trapped light and also the Purcell enhancement of spontaneous emission. The findings in this Letter suggest an easier way for the realization of more energy-efficient DUV LEDs which offer the advantage of high emission for various applications in disinfection and sterilization.
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Background The medical literature has demonstrated the importance of healthcare-associated infections (HAIs) and their negative consequences which are often due to inadequate management of cleaning, disinfection and sterilization. Stethoscope is the most used medical device in the world. The lack of stethoscope hygiene favors the transmission of microorganisms and can be a potential source of HAIs. This study proposes and evaluates an innovative health technology solution for stethoscopes’ disinfection. Methods A prototype of a portable and …
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An open-source 3-D printable laboratory sample rotator mixer is developed here in two variants that allow users to opt for the level of functionality, cost saving and associated complexity needed in their laboratories. First, a laboratory sample rotator is designed and demonstrated that can be used for tumbling as well as gentle mixing of samples in a variety of tube sizes by mixing them horizontally, vertically, or any position in between. Changing the mixing angle is fast and convenient and requires no tools. This device is battery powered and can be easily transported to operate in various locations in a lab including desktops, benches, clean hoods, chemical hoods, cold rooms, glove boxes, incubators or biological hoods. Second, an on-board Arduino-based microcontroller is incorporated that adds the functionality of a laboratory sample shaker. These devices can be customized both mechanically and functionally as the user can simply select the operation mode on the switch or alter the code to perform custom experiments. The open source laboratory sample rotator mixer can be built by non-specialists for under US$30 and adding shaking functionality can be done for under $20 more. Thus, these open source devices are technically superior to the proprietary commercial equipment available on the market while saving over 90% of the costs.
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Survival was measured as a function of the dose of germicidal UV light for the bacteria Escherichia coli, Salmonella typhi, Shigella sonnei, Streptococcus faecalis, Staphylococcus aureus, and Bacillus subtilis spores, the enteric viruses poliovirus type 1 and simian rotavirus SA11, the cysts of the protozoan Acanthamoeba castellanii, as well as for total coliforms and standard plate count microorganisms from secondary effluent. The doses of UV light necessary for a 99.9% inactivation of the cultured vegetative bacteria, total coliforms, and standard plate count microorganisms were comparable. However, the viruses, the bacterial spores, and the amoebic cysts required about 3 to 4 times, 9 times, and 15 times, respectively, the dose required for E. coli. These ratios covered a narrower relative dose range than that previously reported for chlorine disinfection of E. coli, viruses, spores, and cysts.
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The objective of this study was to test the hypothesis that enhanced ultraviolet germicidal irradiation (eUVGI) installed in our neonatal intensive care unit (NICU) heating ventilation and air conditioning system (HVAC) would decrease HVAC and NICU environment microbes, tracheal colonization and ventilator-associated pneumonia (VAP). The study was designed as a prospective interventional pre- and post-single-center study. University-affiliated Regional Perinatal Center NICU. Intubated patients in the NICU were evaluated for colonization, and a high-risk sub-population of infants <30 weeks gestation ventilated for ≥ 14 days was studied for VAP. eUVGI was installed in the NICU's remote HVACs. The HVACs, NICU environment and intubated patients' tracheas were cultured pre- and post-eUVGI for 12 months. The high-risk patients were studied for VAP (positive bacterial tracheal culture, increased ventilator support, worsening chest radiograph and ≥ 7 days of antibiotics). Pseudomonas, Klebsiella, Serratia, Acinetobacter, Staphylococcus aureus and Coagulase-negative Staphylococcus species were cultured from all sites. eUVGI significantly decreased HVAC organisms (baseline 500,000 CFU cm(-2); P=0.015) and NICU environmental microbes (P<0.0001). Tracheal microbial loads decreased 45% (P=0.004), and fewer patients became colonized. VAP in the high-risk cohort fell from 74% (n=31) to 39% (n=18), P=0.04. VAP episodes per patient decreased (Control: 1.2 to eUVGI: 0.4; P=0.004), and antibiotic usage was 62% less (P=0.013). eUVGI decreased HVAC microbial colonization and was associated with reduced NICU environment and tracheal microbial colonization. Significant reductions in VAP and antibiotic use were also associated with eUVGI in this single-center study. Large randomized multicenter trials are needed.
Purpose of review: This article reviews 'no touch' methods for disinfection of the contaminated surface environment of hospitalized patients' rooms. The focus is on studies that assessed the effectiveness of ultraviolet (UV) light devices, hydrogen peroxide systems, and self-disinfecting surfaces to reduce healthcare-associated infections (HAIs). Recent findings: The contaminated surface environment in hospitals plays an important role in the transmission of several key nosocomial pathogens including methicillin-resistant Staphylococcus aureus, vancomycin-resistant Enterococcus spp., Clostridium difficile, Acinetobacter spp., and norovirus. Multiple clinical trials have now demonstrated the effectiveness of UV light devices and hydrogen peroxide systems to reduce HAIs. A limited number of studies have suggested that 'self-disinfecting' surfaces may also decrease HAIs. Summary: Many studies have demonstrated that terminal cleaning and disinfection with germicides is often inadequate and leaves environmental surfaces contaminated with important nosocomial pathogens. 'No touch' methods of room decontamination (i.e., UV devices and hydrogen peroxide systems) have been demonstrated to reduce key nosocomial pathogens on inoculated test surfaces and on environmental surfaces in actual patient rooms. Further UV devices and hydrogen peroxide systems have been demonstrated to reduce HAI. A validated 'no touch' device or system should be used for terminal room disinfection following discharge of patients on contact precautions. The use of a 'self-disinfecting' surface to reduce HAI has not been convincingly demonstrated.
As the successful free and open-source process is being applied to hardware, an opportunity has arisen to radically reduce the cost of experimental research in the sciences. This book is relevant to every scientist and engineer who does experimental research and employees of scientific funding agencies. A revolution is occurring where formally highly specialized, high-cost scientific equipment can be fabricated using digital designs at factor of 10–100 cost reductions. This makes science much more accessible to the general population, DIY and amateur scientists, grade school science labs, etc. It also reduces costs for our most advanced research institutes. This chapter defines the basic terms of open-source software and discusses the rise of the open-source hardware revolution and how it impacts science.
Background There is growing interest in the use of no-touch automated room decontamination devices within healthcare settings. Xenex PX-UV is an automated room disinfection device using pulsed ultraviolet (UV) C radiation with a short cycle time. Aim To investigate the microbiological efficacy of this device when deployed for terminal decontamination of isolation rooms within a clinical haematology unit. Methods The device was deployed in isolation rooms in a clinical haematology unit. Contact plates were applied to common touch points to determine aerobic total colony counts (TCCs) and samples collected using Polywipe™ sponges for detection of vancomycin-resistant enterococci (VRE). Results The device was easy to transport, easy to use, and it disinfected rooms rapidly. There was a 76% reduction in the TCCs following manual cleaning, with an additional 14% reduction following UV disinfection, resulting in an overall reduction of 90% in TCCs. There was a 38% reduction in the number of sites where VRE was detected, from 26 of 80 sites following manual cleaning to 16 of 80 sites with additional UV disinfection. Conclusions The Xenex PX-UV device can offer a simple and rapid additional decontamination step for terminal disinfection of patient rooms. However, the microbiological efficacy against VRE was somewhat limited.
Tru-D™ is an automated room disinfection device that uses ultraviolet-C radiation to kill micro-organisms. The device was deployed in six side-rooms and an operating theatre. In a cleaned, unoccupied operating theatre, Tru-D eradicated all organisms from the environment. Using artificially seeded Petri dishes with meticillin-resistant Staphylococcus aureus, multi-resistant acinetobacter and vancomycin-resistant enterococci, the mean log10 reductions were between three and four when used at 22,000μWs/cm(2) reflected dose. The device was easy to transport and utilize, and able to disinfect rooms rapidly. This appears to be a practical alternative technology to other 'no-touch' automated room disinfection systems.