This paper reports the design and experimental analysis of dielectrophoretic traps composed of four microfabricated gold
electrodes excited in a quadrupolar fashion surrounding the electrodes with novel geometries for object detection.
Implemented with a simple single-layer metal process, our microchip device makes the quadrupolar collection electrodes
and detecting electrodes coplanar. Our scheme could not only make the collection system and the detection system in a
chip integrated more easily, but provide possibility to synchronize the two systems and shorten response time. It is found
that, at the low medium conductivities used, the existence of annular or parallel track detecting electrodes can hardly
influence the separation efficiency, which shows that it is possible to drive targets to the object region rapidly by
dielectrophoretic force while all the electrodes within a whole chip are coplanar. Dielectrophoresis effects of colloidal
polystyrene particle are enhanced increasing the frequency of stimulating electric field.
Dielectrophoresis (DEP) is a promising method for the automated separation of biological cells in a miniaturized format.
This technology allows cells to be manipulated electronically while suspended in a microfluidic channel embedded in a
silicon lab-on-chip. Different dielectrophoretic configurations have been designed and fabricated using micro-electro-mechanical-
systems (MEMS) technology, which are investigated comparatively on their function principles and
separation efficiencies. DEP responses of colloidal polystyrene particles with the diameters of 10.9µm and 21.3µm
suspended in deionized water are measured. It is found that, at the low medium conductivities used, global or local
extreme points of electric fields can be configurated dependent on shapes and geometry sizes of electrodes. In addition,
all the new phenomena appeared during whole experiment are observed, which may provide novel methods to separate
micro particles.
Polymerase chain reaction (PCR) microvessel, capillary electrophoresis (CE) microchannel and impedance electrodes were integrated in a monolithic biochip. This paper reports on the detailed designs and fabrications of the PCR-CE-detector integrated biochip. The CE microchannel and PCR microvessel were fabricated with PDMS poured on a master made by SU-8 photoresist. The electrode plate was integrated with Au heater and temperature sensor for PCR amplification, electrodes for CE separation and impedance detection. The structure of the microfluidic channel was introduced and the impedance of microelectrodes on the chip was simulated.
There are considerable interests in integrating Polymerase chain reaction (PCR) on a microchip can have much fast heating and cooling rate, the delicacy in its structure makes the PCR experiment difficult and cracks often occur particularly for the thin membrane type of PCR chips. Design study and experiment of silicon PCR chips are presented with the aim of identifying the problems encountered in experiment and finding an optimum chip structure. Heating characteristics of four different heater designs have been compared, so have the PCR chambers with fixed frame and with suspended frame. The thermal stress analysis has shown that the structure and heater design can make a significant difference in heating characteristics and in reducing the failure of PCR chips. Different solutions to reduce PCR chip failure have been proposed. One of the solutions was implemented in the experiment, confirming the design study results. Silicon PCR chips have been fabricated. Thermal cycling and initial DNA amplification results are presented.
The PCR amplification is based on multiple temperature cycles of DNA synthesis; each includes denaturation of the template, annealing of the primers to complementary sites in the template and primer extension. The key technique of PCR amplification is the heating control in design and fabrication of its chip form. The specifications of the chip are heat properties. In this paper the heat properties of a micro PCR vessel integration heater and temperature sensor was introduced. The temperature distribution of the vessel was simulated with software tool IntelliSuite. The temperatures cycles were measured and the time response of the chip was discussed. It is found that the integrate micro vessel is a very useful tool not only for DNA synthesis but also as a biochemical reactor for many other biological and chemical analyses.
Polymerase chain reaction (PCR) on a microchip has drawn considerable attention in recent years. Although a microchip can have must fast heating and cooling rate, the delicacy in its structure makes the PCR experiment difficult and cracks often occurs particularly for the thin membrane type of PCR chips. Electrothermal modeling of PCR chips is presented using commercial MEMS software tool IntelliSuiteTM, with the aim of identifying the problems encountered in experiment and finding an optimum chip structure. Heating characteristics of four different heater designs have been compared, so have the PCR chambers with fixed frame and with suspended frame. The thermal stress analysis has shown that the structure and heater design can make significant difference in heating characteristics and in reducing the failure of PCR chips. The computer simulation has confirmed what has been found in experiment the reason of membrane cracks. Improvement in PCR chip design has been proposed.
Access to the requested content is limited to institutions that have purchased or subscribe to SPIE eBooks.
You are receiving this notice because your organization may not have SPIE eBooks access.*
*Shibboleth/Open Athens users─please
sign in
to access your institution's subscriptions.
To obtain this item, you may purchase the complete book in print or electronic format on
SPIE.org.
INSTITUTIONAL Select your institution to access the SPIE Digital Library.
PERSONAL Sign in with your SPIE account to access your personal subscriptions or to use specific features such as save to my library, sign up for alerts, save searches, etc.