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ZEUSSS: Zero Energy Ubiquitous Sound Sensing Surface Leveraging Triboelectric Nanogenerator and Analog Backscatter Communication

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ZEUSSS (Zero Energy Ubiquitous Sound Sensing Surface), allows physical objects and surfaces to be instrumented with a thin, self-sustainable material that provides acoustic sensing and communication capabilities. We have built a prototype ZEUSSS tag using minimal hardware and flexible electronic components, extending our original self-sustaining SATURN microphone with a printed, flexible antenna to support passive communication via analog backscatter. ZEUSSS enables objects to have ubiquitous wire-free battery-free audio based context sensing, interaction, and surveillance capabilities.
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ZEUSSS : Zero Energy Ubiquitous Sound Sensing Surface
Leveraging Triboelectric Nanogenerator and Analog
Backscatter Communication
Nivedita Arora
School of Interactive Computing
Georgia Institute of Technology, USA
nivedita.arora@gatech.edu
Gregory D. Abowd
School of Interactive Computing
Georgia Institute of Technology, USA
abowd@gatech.edu
ABSTRACT
ZEUSSS (
Z
ero
E
nergy
U
biquitous
S
ound
S
ensing
S
urface),
allows physical objects and surfaces to be instrumented with a
thin, self-sustainable material that provides acoustic sensing
and communication capabilities. We have built a prototype
ZEUSSS tag using minimal hardware and flexible electronic
components, extending our original self-sustaining SATURN
microphone [3] with a printed, flexible antenna to support pas-
sive communication via analog backscatter. ZEUSSS enables
objects to have ubiquitous wire-free battery-free audio based
context sensing, interaction, and surveillance capabilities.
ACM Classification Keywords
Human-centered computing: Interaction devices—Sound-
based input / output; Hardware: Communication hardware,
interfaces and storage—Wireless integrated network sensors
Author Keywords
Battery-free Microphone; Analog Backscatter
Communication; TENG (Triboelectric Nanogenerator);
Flexible electronics
INTRODUCTION
Physical surfaces and objects enhanced with acoustic sensing
and communication capabilities provide an opportunity for an
unprecedented understanding of human behavior as well as
novel ways of interaction and control in our environment [1,
2, 22].
A practical design solution for such an ambitious vision re-
quires system-level innovation. The form-factor of electronics
- for sensing and communication - should be such that it can
be easily embedded into or on top of any object [7, 13]. The
system design should be self-sustainable from an energy per-
spective, requiring no battery maintenance [15, 8]. In addition,
the system should be low-cost and require minimal hardware
to provide manufacturing scalability in the future. Over the
last decade we have witnessed technological progress on all
these fronts. Advances in materials and additive fabrication
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UIST’18 Adjunct, October 14–17, 2018, Berlin, Germany.
Copyright © 2018 Association of Computing Machinery.
ACM ISBN 978-1-4503-5949-8/18/10 ...$15.00.
http://dx.doi.org/10.1145/3266037.3266108
techniques have enabled electronic components for communi-
cation [18, 6, 5] and sensing [21, 20, 10, 9] to be thin and flexi-
ble in form factor [23]. In addition, techniques for battery-free
communication through ambient [11, 19] or analog backscat-
ter [17] have demonstrated ground-breaking self-sustainable
systems [12, 16]. These advances motivate our desire to unite
the separate themes of self-sustainable sensing and commu-
nication and build prototypes of easily-instrumented physical
surfaces and objects.
This paper examines more closely the design requirements and
research progress for audio sensing to build ZEUSSS, Zero
Energy Ubiquitous Sound Sensing Surface. Specifically, we
explore opportunities to create a low-cost and flexible material
that can provide acoustic sensing and wireless communication
without the need of a local battery source.
SYSTEM DESIGN
Figure 1: ZEUSSS Tag (a) SATURN : a thin and flexible self-
powered microphone leveraging Triboelectric Nanogenerator
(TENG) [3] (b) SATURN connected to printed antenna using
n-JFET and impedance matching circuit
Our recently published work, the SATURN
1
(Self-powered
Audio Triboelectric Ultra-thin Rollable Nanogenerator) mi-
crophone, see Figure 1(a), demonstrates design, fabrication,
evaluation, and use of a self-powered microphone that is thin,
1SATURN video: www.youtube.com/watch?v=OLuZHpa_FIM
Poster Session
UIST'18 Adjunct, October 14–17, 2018, Berlin, Germany
81
flexible, and easily manufactured [3]. SATURN leverages the
design of Triboelectric Nanogenerator (TENG) which relies
on combined triboelectrification and electrostatic induction
effects, to convert tiny vibrations induced on the surface of an
object by sound, or any other vibration, into an electric signal
output.
Electrically, SATURN is a variable capacitor and voltage gen-
erator source, similar to the common electret microphone. As
shown in Figure 1(b), we built a ZEUSSS tag to implement
analog backscatter communication such that the sensed quan-
tity, audio in our case, can directly modify the impedance of
the 915 MHz printed dipole antenna. This is done by connect-
ing SATURN to the gate terminal of the JFET with no DC
voltage on the drain terminal. The voltage across the drain and
source terminals of the JFET,
VDS
= 0, biases the device in the
triode region, making it a voltage-regulated resistor, changing
the impedance of the circuit as a function of the sensed audio.
Figure 2: Experimental setup of ZEUSSS consisting of self-
powered flexible microphone communication tag and USRP-
SDR based RFID reader
Inspired by recent battery-free audio communications work
[16, 17], the ZEUSSS tag communicates sound to a commer-
cial USRP-based RFID reader at 915 MHz in a purely analog
mode using amplitude modulation. According to backscatter
theory [4], the sound received is a function of a reflection
coefficient
τ
of the backscattered signal. The sound at the
USRP end is extracted using a band pass filter and evaluated
using Perceptual Evaluation of Sounds Quality (PESQ) scores
[14]. The backscattered signal quality is directly dependent
on the original signal produced by the SATURN microphone
and inversely on the distance between the reader and the tag.
To maintain sound quality for longer distance communication,
we would increase the SATURN patch size to increase the
backscattered signal strength.
APPLICATIONS
The thin and flexible form factor of ZEUSSS allows it to be
placed on top of different physical surfaces for self-sustainable
audio sensing and communication. We imagine scenarios
where many different ZEUSSS tags in the home can cheaply
extend the range of audio input for home assistants (e.g., Ama-
zon Echo or Google Home), which are currently limited to
a room. ZEUSSS could be a ubiquitous battery-free audio
surveillance microphone which can determine context like –
is someone is present in the room, who is present, listen in on
sound stimuli like conversations or music. Multiple ZEUSSS
Figure 3: Applications for ZEUSSS
tags in a room would allow for location tracking of sound
sources or even acoustic characterization of a physical space.
In addition to audio sensing, ZEUSSS tag can also be used
as a contact microphone to sense input touches, such that dif-
ferent speed or force of taps could be detected. This could
extend input gesture and control capability for IoT applica-
tions like switching light on or off or changing brightness.
ZEUSSS could be used as an authentication device, where
users can speak, blow, whistle, tap or create unique combi-
nation of these as their password to do a remote login. With
applications in wireless self-sustainable remote interaction,
control, surveillance, localization and authentication ZEUSSS
has great potential for impact in the UIST community in the
future.
FUTURE WORK
Triboelectric Nanogenerators (TENG) have attracted a great
deal of attention as a self-powered sensor for detecting varied
mechanical stimuli, such as sound, physical touch, biological
movement, physiological sensing, linear displacement, rota-
tion, and wind speed. All of these initial demonstrations have
required a power intensive device, such as a micro-controller
or oscilloscope, for sensor data collection, which reduces the
overall self-powered advantage of the TENG sensor. ZEUSSS
is the very first example of a completely self-powered sens-
ing and data collection solution based on the combination of
TENG and analog-backscatter communication. Such an ar-
chitecture can be further expanded for passive sensing and
communication of many different mechanical forces and vi-
brations in our environment, which promises to open doors for
new applications in interaction, control and contextual sensing
domain.
CONCLUSION
ZEUSSS is a work in progress where we are currently building
our prototype to optimize the design parameters which would
enable it to sense sound, communicate, and be instrumented
on physical surfaces. The new application avenues which
ZEUSSS offers for interaction, control and surveillance makes
it potentially a compelling work for the UIST community.
REFERENCES
1. Gregory D Abowd. 2016. Beyond Weiser: From
ubiquitous to collective computing. Computer 49, 1
(2016), 17–23.
Poster Session
UIST'18 Adjunct, October 14–17, 2018, Berlin, Germany
82
2. Gregory D Abowd and Elizabeth D Mynatt. 2005.
Designing for the human experience in smart
environments. Smart environments: technologies,
protocols, and applications (2005), 151–174.
3. Nivedita Arora, Steven L. Zhang, Fereshteh Shahmiri,
Diego Osorio, Yi-Cheng Wang, Mohit Gupta, Zhengjun
Wang, Thad Starner, Zhong Lin Wang, and Gregory D.
Abowd. 2018. SATURN: A thin and flexible self-powered
microphone leveraging triboelectric nanogenerator.
Proceedings of the ACM on Interactive, Mobile, Wearable
and Ubiquitous Technologies 2 (2018), 27.
4. RC Hansen. 1989. Relationships between antennas as
scatterers and as radiators. Proc. IEEE 77, 5 (1989),
659–662.
5. Jimmy G Hester, Sangkil Kim, Jo Bito, Taoran Le, John
Kimionis, Daniel Revier, Christy Saintsing, Wenjing Su,
Bijan Tehrani, Anya Traille, and others. 2015. Additively
manufactured nanotechnology and origami-enabled
flexible microwave electronics. Proc. IEEE 103, 4 (2015),
583–606.
6. Haiying Huang. 2013. Flexible wireless antenna sensor:
A review. IEEE sensors journal 13, 10 (2013),
3865–3872.
7. Vikram Iyer, Justin Chan, and Shyamnath Gollakota.
2017. 3D printing wireless connected objects. ACM
Transactions on Graphics (TOG) 36, 6 (2017), 242.
8. Aman Kansal, Jason Hsu, Sadaf Zahedi, and Mani B
Srivastava. 2007. Power management in energy
harvesting sensor networks. ACM Transactions on
Embedded Computing Systems (TECS) 6, 4 (2007), 32.
9. Saleem Khan, Leandro Lorenzelli, and Ravinder S
Dahiya. 2015. Technologies for printing sensors and
electronics over large flexible substrates: a review. IEEE
Sensors Journal 15, 6 (2015), 3164–3185.
10. Simon J Leigh, Robert J Bradley, Christopher P Purssell,
Duncan R Billson, and David A Hutchins. 2012. A
simple, low-cost conductive composite material for 3D
printing of electronic sensors. PloS one 7, 11 (2012),
e49365.
11. Vincent Liu, Aaron Parks, Vamsi Talla, Shyamnath
Gollakota, David Wetherall, and Joshua R Smith. 2013.
Ambient backscatter: wireless communication out of thin
air. In ACM SIGCOMM Computer Communication
Review, Vol. 43. ACM, 39–50.
12. Saman Naderiparizi, Mehrdad Hessar, Vamsi Talla,
Shyamnath Gollakota, and Joshua R Smith. 2018.
Towards battery-free HD video streaming. In 15th
USENIX Symposium on Networked Systems Design and
Implementation (NSDI 18).
13.
Hiroki Ota, Sam Emaminejad, Yuji Gao, Allan Zhao, Eric
Wu, Samyuktha Challa, Kevin Chen, Hossain M Fahad,
Amit K Jha, Daisuke Kiriya, and others. 2016.
Application of 3D printing for smart objects with
embedded electronic sensors and systems. Advanced
Materials Technologies 1, 1 (2016).
14. Scott Pennock. 2002. Accuracy of the perceptual
evaluation of speech quality (PESQ) algorithm. Proc. Of
MESAQIN 25 (2002).
15. Thad Starner. 2001. The challenges of wearable
computing: Part 1. Ieee Micro 21, 4 (2001), 44–52.
16. Vamsi Talla, Bryce Kellogg, Shyamnath Gollakota, and
Joshua R Smith. 2017. Battery-free cellphone.
Proceedings of the ACM on Interactive, Mobile, Wearable
and Ubiquitous Technologies 1, 2 (2017), 25.
17. Vamsi Talla and Joshua R Smith. 2013. Hybrid
analog-digital backscatter: A new approach for
battery-free sensing. In RFID (RFID), 2013 IEEE
International Conference on. IEEE, 74–81.
18. MM Tentzeris. 2008. Novel paper-based inkjet-printed
antennas and wireless sensor modules. In Microwaves,
Communications, Antennas and Electronic Systems, 2008.
COMCAS 2008. IEEE International Conference on.
IEEE, 1–8.
19. Nguyen Van Huynh, Dinh Thai Hoang, Xiao Lu, Dusit
Niyato, Ping Wang, and Dong In Kim. 2018. Ambient
backscatter communications: A contemporary survey.
IEEE Communications Surveys & Tutorials (2018).
20. Zhong Lin Wang. 2015. Triboelectric nanogenerators as
new energy technology and self-powered
sensors–Principles, problems and perspectives. Faraday
discussions 176 (2015), 447–458.
21. Zhong Lin Wang and Aurelia Chi Wang. 2018.
Triboelectric Nanogenerator for Self-Powered Flexible
Electronics and Internet of Things. In Meeting Abstracts.
The Electrochemical Society, 1533–1533.
22. Mark Weiser. 1991. The Computer for the 21st Century.
Scientific American 265, 3 (1991), 94–105.
23. William S Wong and Alberto Salleo. 2009. Flexible
electronics: materials and applications. Vol. 11. Springer
Science & Business Media.
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UIST'18 Adjunct, October 14–17, 2018, Berlin, Germany
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... Top: SATURN -thin and flexible self-powered microphone[4] , Bottom: ZEUSSS : Zero-energy Ubiquitous Sound Sensing Surface[3]. ...
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Printing sensors and electronics over flexible substrates are an area of significant interest due to low-cost fabrication and possibility of obtaining multifunctional electronics over large areas. Over the years, a number of printing technologies have been developed to pattern a wide range of electronic materials on diverse substrates. As further expansion of printed technologies is expected in future for sensors and electronics, it is opportune to review the common features, the complementarities, and the challenges associated with various printing technologies. This paper presents a comprehensive review of various printing technologies, commonly used substrates and electronic materials. Various solution/dry printing and contact/noncontact printing technologies have been assessed on the basis of technological, materials, and process-related developments in the field. Critical challenges in various printing techniques and potential research directions have been highlighted. Possibilities of merging various printing methodologies have been explored to extend the lab developed standalone systems to high-speed roll-to-roll production lines for system level integration.
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