In this chapter, the lab-on-a-tube surface micromachining technology will be used to fabricate a flexible implantable microtemperature sensor for hyperthermia application and a three-electrode system on a polymer tube surface for glucose monitoring application. This micromachining process is based on two homemade equipments: a spray coating equipment and a programmable UV 3D projection lithography system with alignment. In the spray coating system, there is a heater nozzle next to the spray nozzle for real-time heating. Pure nitrogen is flowed through the heater nozzle, warmed up and sprayed onto the tube substrate surface. The programmable UV lithography equipment for cylindrical substrate mainly consists of four parts: a uniform illumination system, a reduced projection lithography system, a synchronized motion stage system, and a Charge-Coupled Device (CCD) multilayer alignment system which is used to observe simultaneously the projected mask’s patterns and those ever fabricated on the tube. Using the developed lab-on-a-tube surface micromachining technology, an implantable flexible microtemperature sensor and a three-electrode microstructure are successfully fabricated on the flexible polymer tube with 330 μm outer diameter, respectively. The test temperature coefficient of resistance (TCR) of the temperature sensor is 0.0034/°C. The measured cyclic voltammetry curve shows that the three-electrode system has a good redox property.
Part of the book: Thin Film Processes