Design and implementation of collagen-based capacitive relative humidity sensors

In the search for novel organic and biocompatible materials, we propose to use collagen as a novel dielectric relative humidity sensing material. The goal of this work is to assert the utility of collagen as an inexpensive alternative for more traditional dielectric materials. Coming from the bones, tendons, and skin of bovine and pigs, this by-product of the meat and leather industry presents itself as an appealing candidate. No study has yet to explore the potential use of collagen in sensing systems. We have successfully patterned thin film Collagen layers into strips which reside in between copper electrodes, resulting in interdigitated planar capacitor structures. We have measured the capacitance change of the sensing capacitors under 50% and 75% relative humidity at different temperatures. The response time was found to be within seconds. With a proper temperature compensation scheme, collagen can be used as a biocompatible relative humidity sensor.