A three dimensional Multi-Walled Carbon Nanotube based thermal sensor on a flexible Parylene substrate

We present the first design, fabrication and testing results from a three dimensional multi-walled carbon nanotube based thermal sensor fabricated on a flexible parylene-C substrate. Parylene-C is an inert, biocompatible, optically transparent, room temperature deposited polymer with a high mechanical strength, yet is rarely used as a flexible substrate. By utilizing a 2 mask process, we have manufactured a versatile microplatform for nanoscale assembly and then by utilizing dielectrophoretic assembly, incorporate MWNTs onto the platform in a 3D manner. The MWNTs are next encapsulated using a thin Parylene-C layer that acts as an environmental barrier and in addition keeps the MWNTs intact. The temperature Coefficient of Resistance of the MWNT sensor is measured to be between -0.21% and -0.66% per degree. The thermal sensor is compact, is very high density and could potentially be used for diverse temperature sensing applications such as in wearable textiles, on non planar surfaces and for in-vivo applications.