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Browsing by Author "Tracey, M.C."
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Analysis and design optimization of an integrated micropump-micromixer operated for bio-MEMS applications
Cortes, Cesar; Azarbadegan, Alireza; Johnston, Ian; Tracey, M.C. (2014-09-07)A generic microfluidic system composed by two single chamber valveless micropumps connected to a simple T-type channel intersection is examined numerically. The characteristics of a feasible valveless micropump have been ... -
Continuously variable mixing-ratio micromixer with elastomer valves
Tan, C. K. L.; Tracey, M.C.; Davis, J. B.; Johnston, I. D. (2005-10)We report a self-contained microfluidic alternate flow injection mixer (AFIM) employing piezoelectrically actuated, PDMS seal-valves to control injection. AFIMs employ pulsatile injection of liquids to enhance interface ... -
Dean flow focusing and separation of small microspheres within a narrow size range.
Johnston, Ian; McDonnell, M.B.; Tan, Christabel; McCluskey, Daniel; Davies, Matthew; Tracey, M.C. (2014-09-01)Rapid, selective particle separation and concentration within the bacterial size range (1–3 μm) in clinical or environmental samples promises significant improvements in detection of pathogenic microorganisms in areas ... -
Dean-flow sample Clean-up to Optimise and Extend the Operational Envelope of Biodetection Systems. : Final report for the Centre for Defence Enterprise Research Project
Tracey, M.C.; Johnston, Ian (University of Hertfordshire, 2011-09-06)This CDE funded research project sought to establish the applicability of microfluidic devices employing 'Dean-flow', a second order flow effect, to the 'clean-up' of real-world aqueous suspension samples prior to their ... -
Design and evaluation of a passive micromixer with curved shape obstacles and grooves in the mixing channel
Cortes, Cesar; Tracey, M.C. (2014-03-18)Micromixers are key components in several micro electro-mechanical and lab-on-a-chip systems, which are increasingly applied in fields such as chemistry, chemical synthesis, bio-technology and environment control. A CFD-based ... -
Dual independent displacement-amplified micropumps with a single actuator
Tracey, M.C.; Johnston, I. D.; Davis, J. B.; Tan, C. K. L. (2006-08)We report a dual-micropump structure operated by a single actuator element. The constituent micropumps are a form of micro throttle pump (MTP) comprising a narrow flow channel incorporating two microthrottles. We term this ... -
Elastomer-glass micropump employing active throttles
Johnston, I. D.; Davis, J.B.; Richter, R.; Herbert, G. I.; Tracey, M.C. (2004)We report a reciprocating microfluidic pump, the Micro Throttle Pump (MTP), constructed in a relatively uncomplicated manner from glass and microstructured poly(dimethylsiloxane) (PDMS). Unconventionally, the MTP employs ... -
Electromagnetic Actuated Stiring in Microbioreactor Enabling Easier Multiplexing and Flexible Device Design
Davies, M. J.; Munro, Ian; Tan, Christabel; Tracey, M.C.; Szita, Nicolas (2014-09-07)The development of a novel electromagnetically (EM) actuated stirring method, for use in microbioreactors, is reported. Mixing in microbioreactors is critical to ensure even distribution of nutrients to microorganisms and ... -
Electromagnetic Stirring in a Microbioreactor with Non-conventional Chamber Morphology and Implementation of Multiplexed Mixing
Tan, Christabel; Davies, Matthew; McCluskey, Daniel; Munro, Ian; Nweke, Mauryn; Tracey, M.C.; Szita, Nicolas (2015-10-31)Background: Microbioreactors have recently emerged as novel tools for early bioprocess development. Mixing lies at the heart of bioreactor operation (at all scales), and the successful implementation of micro-stirring ... -
Increasing pumping efficiency in a micro throttle pump by enhancing displacement amplification in an elastomeric substrate
Fujiwara, T.; Johnston, I.D.; Tracey, M.C.; Tan, C.K.L (2010)Fluid transport is accomplished in a micro throttle pump (MTP) by alternating deformation of a micro channel cast into a polydimethylsiloxane (PDMS) elastomeric substrate. The active deformation is achieved using a bimorph ... -
Low-cost credit card-based microfluidic devices for magnetic bead immobilisation
Coudron, Loic; Johnston, Ian; Tan, Christabel; Tracey, M.C. (2013-01)We report a simple low-cost magnetic microfluidic device for magnetic bead separation and immobilisation. One dimensional arrays of localised high magnetic field gradients are constructed at the interfaces between regions ... -
Mechanical Characterisation of Bulk Sylgard 184 for Microfluidics and Microengineering.
Johnston, Ian; McCluskey, Daniel; Tan, Christabel; Tracey, M.C. (2014-02-28)Polydimethylsiloxane (PDMS) elastomers are extensively used for soft lithographic replication of microstructures in microfluidic and micro engineering applications. Elastomeric microstructures are commonly required to ... -
Micro throttle pump employing displacement amplification in an elastomeric substrate
Johnston, I. D.; Tracey, M.C.; Davis, J. B.; Tan, C. K. L. (2005-10)We report a micro throttle pump (MTP) with enhanced throttling resulting from beneficial deformation of its elastomer substrate. In the MTP reported, this has doubled the effective deflection of the piezo electric (PZT) ... -
Microfluidic solid phase suspension transport with an elastomer-based, single piezo-actuator, micro throttle pump
Johnston, I. D.; Tracey, M.C.; Davis, J. B.; Tan, C. K. L. (2005)We report a Micro Throttle Pump (MTP) which has been shown to pump 5 mm diameter polystyrene beads at a concentration of 4.5 x 10(7) beads ml(-1). This new MTP design is constructed in a straightforward manner and actuated ... -
Microfluidics based microcytometer: interfacing microfluidics with macrofluidics
Tracey, M.C.; Johnston, I.D.; Greenaway, R.; Sutton, N.; Doetzel, W.A. (Springer Nature, 1998) -
A microfluidics-based instrument for cytomechanical studies of blood
Tracey, M.C.; Sutton, N.; Johnston, I.D.; Doetzel, W.A. (Institute of Electrical and Electronics Engineers (IEEE), 2000) -
Multi-Channel Patterning of Antibodies on a Sensor Surface for Simultaneous Detection of Pathogens and Toxins
Davies, M. J.; McDonnell, M.B.; Johnston, I.D.; Perkins, E.A.; Tracey, M.C. (2010)This poster describes the development of a micro-engineered, PDMS/PMMA composite patterning device for the flow immobilisation of up to 16 separate antibody stripes on a single sensor chip surface. Results for a preliminary ... -
A Novel Instrument for Studying the Flow Behaviour of Erythrocytes through Microchannels Simulating Human
Sutton, N.; Tracey, M.C.; Johnston, I.D.; Greenaway, R.; Rampling, M.W. (1997)A novel instrument has been developed to study the microrheology of erythrocytes as they flow through channels of dimensions similar to human blood capillaries. The channels are produced in silicon substrates using ... -
The production of precision silicon micromachined non-spherical particles for aerosol studies
Kaye, Paul H.; Micheli, F.; Tracey, M.C.; Hirst, E.; Gundlach, A.M. (1992)A variety of accurately defined non-spherical particles have been produced in silicon dioxide and polycrystalline silicon using the process of silicon micromachining. The particles are of lengths 3μm, 4.5μm, 7.5μm, and ... -
A silicon micromachined device for use in blood cell deformability studies
Tracey, M.C.; Greenaway, R. S.; Das, A.; Kaye, Paul H.; Barnes, A. J. (1995-08)An application of silicon micromachining to the analysis of blood cell theology is described. The system, based upon a micromachined flow cell, provides a specific measurement of each cell in a statistically significant ...