Fabrication of a Microbiochemical Reactor with Thick Thermal Isolation Layer and Integrated Pt Heater/Sensor in the Microwell

Abstract

We have fabricated a microbiochemical reactor with integrated heater and sensor in the microwell, which is the unlike conventional micromachined biochemical reactors which have an integrated heater and sensor on the backside of the wafer. In order to pattern heater and sensor inside the well, a thick negative Su-8 photo- resist (PR) was used. As a desirable thermal isolation layer at the bottom of the well, we proposed a thick silicon dioxide layer using porous silicon. The temperature distribution in the well for various heater shapes and the effect of the thermal isolation layer was investigated by simulation. Because of the thick thermal isolation layer and Pt heater in the well, we can expect low power consumption and less heat dissipation to the silicon substrate, which is a good thermal conductor, and real-time sensing of reagent.

Design and fabrication of a quasi-ordered nanoporous silicon membrane suitable for thermally induced drug release

“…The meander design is a simple resistor design and serves as the basis for comparison. Indeed, a meander design has been considered previously for heating of the related porous structure [42]. The spiral design allows the heater length with area to be optimum, while the coil design means that hot spots, typically created by sharp, abrupt corners in the heater, are minimized.…”

“…The integration of heaters with PSi has been previously considered for other applications, most notably sensing devices [40], thermal accelerometers [41] as well as a microbiochemical reactor [42]. Indeed, in as early as 1998, Kolev et al reported a proof of concept, mathematical modelling study for a PSi-based pellistor-type catalytic flammable gas sensor fabricated in silicon with a platinum meander heater design [43].…”

“…The model was numerically solved using the implicit alternating-direction model to study the influence of power consumption and the geometry of the structure. The most relevant reported study, to the results reported here, is that of Choi et al where three different designs for a reactor with a thick thermal isolation layer and an integrated platinum heater/sensor is considered [42]. For this example, the heater is fabricated in the base of a cavity and thermally insulated from the supporting silicon substrate by a 20 μm thick oxidized PSi layer and then covered by a layer of silicon dioxide.…”