Kevin John Land

Kevin John Land
University of Pretoria | UP · Department of Electrical, Electronic and Computer Engineering

PhD Microsystems Engineering, University of Freiburg, Germany

About

73
Publications
28,548
Reads
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685
Citations
Additional affiliations
September 2009 - December 2014
University of Freiburg
Position
  • PhD Student
February 2007 - present
Council for Scientific and Industrial Research, South Africa
Position
  • Platform Leader: Microsystems

Publications

Publications (73)
Article
Electrochemical detection of metal cations at paper-based sensors has been suggested as an attractive alternative to current spectroscopic and chromatographic detection techniques due to the ease of fabrication, disposable nature, and low cost. Herein, a novel carbon black (CB), dimethylglyoxime (DMG) ink is designed as an electrode modifier in con...
Article
The development of low‐cost, disposable electrode materials has been at the forefront of sensor technology in recent decades. Paper, offers possibilities for multi‐functional, disposable and economically friendly sensing capabilities and has proved to be a suitable reagent storage and substrate material in paper‐based analytical devices (PADs). In...
Article
Full-text available
A scalable, generic wireless colour detector for point-of-care diagnostics in resource-limited settings is presented. The challenges faced in these settings have limited the effectiveness of point-of-care diagnostics. By combining the growing fields of paper-based diagnostics and printed electronics with Southern African clinic perspectives, a mass...
Article
Full-text available
Paper-based microfluidics is a rapidly developing field with applications for point-of-care disease and environmental diagnostics. In parallel, printed electronics has grown swiftly, particularly for wearable technologies. By combining these fields, fluidic sample processing and control, as well as automated sensing and readout can be integrated on...
Article
Full-text available
The disposable electrochemical sensors were designed and fabricated onto a photo paper substrate in-house. We report a first case use of g-C3N4, which is an emerging material as the most stable carbon-like polymer, explored for application as the electrochemical sensor on heavy metal ion detection. In this work, Bi/g-C3N4 materials were coated on t...
Chapter
It has long been recognised that diagnosis is a critical component of healthcare, and without sufficiently accurate diagnosis treatment is difficult or not possible. Advanced laboratory-based systems have been developed over many years and now for many different analysis requirements and analytes it is possible to get a quantitative analysis. Devel...
Chapter
Paper-based diagnostics usually refers to microfluidic and chemical diagnostic components implemented on paper substrates, with the aim of such devices being able to replace more costly microfluidic diagnostic platforms. Paper provides a model platform on which to develop low-cost diagnostics, as it has intrinsic fluidic properties in addition to b...
Book
This book explores the status of paper-based diagnostic solutions, or Microfluidics 2.0. The contributors explore: how paper-based tests can be widely distributed and utilized by semi-skilled personnel; how close to commercial applications the technology has become, and what is still required to make paper-based diagnostics the game-changer it can...
Article
Lack of access to quality diagnostics remains a major contributor to health burden in resource-limited settings. It has been more than 10 years since ASSURED (affordable, sensitive, specific, user-friendly, rapid, equipment-free, delivered) was coined to describe the ideal test to meet the needs of the developing world. Since its initial publicatio...
Article
This work details manufacturing processes developed to integrate an unpackaged silicon die onto a paper substrate, as part of constructing a hybrid inkjet-printed paper-based circuit. This integration between rigid components and flexible substrates is beneficial in low-cost applications and capitalises on the advantages of both the well-establishe...
Article
Full-text available
Correction for ‘The potential of paper-based diagnostics to meet the ASSURED criteria’ by Suzanne Smith et al. , RSC Adv. , 2018, 8 , 34012–34034.
Article
Full-text available
Paper-based diagnostics have already revolutionized point-of-care approaches for health and environmental applications, by providing low-cost, disposable tools that can be utilized in remote settings. These devices typically consist of microfluidic, chemical, and biological diagnostic components implemented on paper substrates, towards addressing t...
Article
This work explores the practical functionality of ultra-high frequency (UHF) radio frequency identification (RFID) tags screen printed onto various low-cost, flexible substrates. The need for integrated and automated low-cost point-of-care diagnostic solutions has driven the development of automated sensing and connectivity for implementation with...
Article
Background Self-immobilisation of enzymes is a useful way of producing particulate biocatalysts that are easy to recover while still retaining high specific activity. The spherezyme microsphere immobilisation technique is useful in that it provides structured enzyme micro-particles within a specific size range. Herein an alternative micro-fluidics...
Article
The presented work demonstrates novel functionalities of hybrid paper-polymer centrifugal devices for assay performance enhancement that leverage the advantages of both paper-based and centrifugal microfluidic platforms. The fluid flow is manipulated by balancing the capillary force of paper inserts with the centrifugal force generated by disc rota...
Article
We present a simple microfluidic system for rapid screening of Escherichia coli (E. coli) O157:H7 employing the specificity of immunomagnetic separation (IMS) via immiscible filtration assisted by surface tension (IFAST), and the sensitivity of the subsequent adenosine triphosphate (ATP) assay by the bioluminescence luciferin/luciferase reaction. T...
Article
Full-text available
We present the analysis of blister pouches for reagent storage and release into microfluidic devices towards point-of-care blood cell counting applications. Blister pouches provide an effective reagent storage mechanism and can be mounted onto microfluidic cartridges directly. Reagents can be released from blister pouches through automated or manua...
Article
Full-text available
Disposable, low-cost microfluidic cartridges for automated blood cell counting applications are presented in this article. The need for point-of-care medical diagnostic tools is evident, particularly in low-resource and rural settings, and a full blood count is often the first step in patient diagnosis. Total white and red blood cell counts have be...
Conference Paper
Full-text available
The present investigation reports isolation and detection of E. coli O157:H7 employing a simple and portable microfluidic device based on immiscible filtration assisted by surface tension (IFAST) and adenosine triphosphate (ATP) bioluminescence assay. The device demonstrated ca. 90% E. coli isolation with linear responses of bioluminescence signals...
Conference Paper
Full-text available
We present on-chip blister pouches for effective reagent storage and release for microfluidic devices. To our knowledge, this is the first set of data published on pierceable blister devices. Reagent storage, addressed by this work, is of particular interest for point-of-care diagnostic applications in resource limited settings. We address three cr...
Conference Paper
Full-text available
This study describes a novel hybrid paper-polymer centrifugal microfluidic device for pre-concentration of E. coli and lateral flow immunoassay enhancement for water quality verification. The device balances rotational centrifugal force with the capillary force of paper to manipulate fluid flow. The device functions as a low-cost centrifuge to conc...
Conference Paper
Full-text available
This work presents microfluidic cartridges for automated blood cell counting towards a point-of-care (POC) full blood count (FBC). Total white blood cell count (WBC) and red blood cell count (RBC) tests were implemented using low-cost, disposable and mass producible microfluidic cartridges with automated sample introduction and processing steps for...
Conference Paper
Full-text available
Lab-on-a-chip devices are often applied to point-of-care diagnostic solutions as they are low-cost, compact, disposable, and require only small sample volumes. For such devices, various reagents are required for sample preparation and analysis and, for an integrated solution to be realized, on-chip reagent storage and automated introduction are req...
Article
Full-text available
We review the utility of centrifugal microfluidic technologies applied to point-of-care diagnosis in extremely under-resourced environments. The various challenges faced in these settings are showcased, using areas in India and Africa as examples. Measures for the ability of integrated devices to effectively address point-of-care challenges are hig...
Article
Full-text available
Current centralised healthcare models pose many challenges, particularly for developing countries such as South Africa, where travel and time costs make it difficult for patients to seek healthcare, even when urgently needed. To address this issue, point-of-care (PoC) tests, which are performed at or near the site of clinical care, have gained popu...
Conference Paper
Full-text available
We present a plug-and-play toolkit for the rapid assembly of paper-based microfluidic and electronic components for quick prototyping of paper-based components towards point-of-care diagnostic solutions. Individual modules, each with a specific function, have been developed to connect together in different sequences and combinations, allowing for a...
Conference Paper
Full-text available
The use of multiplexed paper sensors for health and environmental monitoring applications continues to rise. Multiplexed devices are capable of detecting multiple disease biomarkers or contaminants from a single sample. These devices make testing simpler, faster and at lower cost. However, challenges, such as the misinterpretation of test results,...
Article
A centrifugal microfluidic platform to develop various microfluidic operations - the first of its kind in South Africa - is presented. Rapid and low-cost prototyping of centrifugal microfluidic disc devices, as well as a set-up to test the devices using centrifugal forces, is described. Preliminary results show that various microfluidic operations...
Conference Paper
Full-text available
We present a visualization pipeline from sample to answer for point-of-care blood cell counting applications. Effective and low-cost point-of-care medical diagnostic tests provide developing countries and rural communities with accessible healthcare solutions [1], and can be particularly beneficial for blood cell count tests, which are often the st...
Article
Full-text available
We present a novel use for channel structures in microfluidic devices, whereby two two-phase emulsions, one created on-chip, the other off-chip, are rapidly mixed with each other in order to allow for the coalescence of one emulsion with the other. This approach has been motivated by the difficulty in introducing aqueous cross linking agents into d...
Conference Paper
Full-text available
Multiplexed or parallelised droplet microfluidic systems allow for increased throughput in the production of emulsions and microparticles, while maintaining a small footprint and utilising minimal ancillary equipment. The current paper demonstrates the design and fabrication of a multiplexed microfluidic system for producing biocatalytic microspher...
Conference Paper
Full-text available
SU-8/Clay nanocomposite is considered as a candidate material for microcantilever sensor fabrication. Organically modified montmorillonite clay nanoparticles are dispersed in the universally used negative photoresist polymer SU-8, for a low cost material, which is also biocompatible. If varying the clay loading of the composite material yields a va...
Article
Full-text available
Microfluidic systems enable precise control over tiny volumes of fluid in a compact and low-cost form, thus providing the ideal platform on which to develop point-of-care diagnostic solutions. Centrifugal microfluidic systems, also referred to as lab-on-a-disc or lab-on-a-CD systems, provide a particularly attractive solution for the implementation...
Conference Paper
Full-text available
A centrifugal microfluidic platform to develop various microfluidic operations – the first of its kind in South Africa – is presented. Rapid and low-cost prototyping of centrifugal microfluidic disc devices, as well as a set-up to test the devices using centrifugal forces, is described. Preliminary results show that various microfluidic operations...
Conference Paper
We present an on-chip method for preparing cross-linked protein microspheres. When prepared from a solution of bovine serum albumin (BSA) consisting of lipase, the microspheres showed varying degrees of hydrolytic activity on two pnitrophenyl ester substrates.
Conference Paper
Full-text available
There is an inherent trade-off between cost and operational integrity of microfluidic components, especially when intended for use in point-of-care devices. We present an analysis system developed to characterise microfluidic components for performing blood cell counting, enabling the balance between function and cost to be established quantitative...
Article
Full-text available
Optical microscopy is widely accepted as one of the gold standards in disease diagnosis. However, factors such as cost and the need for a trained eye limit the prevalence of such equipment, particularly in resource-limited areas such as rural clinics. Lensless microscopy, which is based on principles of digital holography, has illustrated the possi...
Article
Full-text available
A method to easily manufacture and assemble a polydimethylsiloxane (PDMS) based microfluidic device is described. The method uses low cost materials and re-usable laser cut polymethyl methacrylate (PMMA) parts. In addition, the thickness of PDMS layers can be controlled and both PDMS layer surfaces are flat, which allows for multi-layer PDMS struct...
Article
Full-text available
The production of water-in-oil (w/o) emulsions in T-junction microfluidic channels was studied through experiments and computational fluid dynamics (CFD). w/o emulsions were produced in the microchannels from deionised water and mineral oil. The interfacial tension of the system was controlled to ~ 0.003 N/m using oil-soluble surface active agent (...
Article
Full-text available
Polydimethylsiloxane (PDMS) is prone to bio-fouling because of its hydrophobic surface. This results in the non-specific adsorption of proteins and other bio materials. The adsorption causes modification on the PDMS surface which becomes a problem in applications which require hydrophobic surface and the use of proteins. PDMS blocks were treated wi...
Article
Full-text available
This paper discusses the experimental observation of capillary instabilities of two-phase flow in a microfluidc T-junction. These instabilities are analogous to the classical Plateau- Rayleigh instabilities. The experiments were carried out with mineral oil and water in a rectangular microchannel of 100 μm and depth of 75 μm. The interfacial tensio...
Article
Copyright of this article belongs to the authors. Microfluidics is a multi-disciplinary field that deals with the behaviour, control and manipulation of fluids constrained to sub-millilitre volumes. It is proving to be a useful tool for biological studies, affording advantages such as reduced cost, faster reaction times and process-specific designs...