3D Printed Biocapacitors for Sensing and Actuation

Abstract

This thesis explored the synthesis of conductive hydrogels and the fabrication of flexible, transparent, biocompatible capacitor devices for sensing and actuation applications using a combination of calcium alginate hydrogel and polyvinylidene fluoride film. Under applied voltages with amplitudes up to 100VP P net displacement was < 1µm, likely suggesting that µm and mm strains could be observed in the kilovolt range. Experimental results were consistent with theoretical models, which also predict that net displacement should be on the order of 10nm for this voltage range. The devices were also examined as motion sensors through their capacitance dependence on applied strain. Preliminary tests showed 30% strain failed to generate measurable change in capacitance, however the lack of capacitance change was found to be due to gel degredation under applied voltage during testing. In summary, this thesis found that small, flexible, biocompatible, and low-power devices could be created that have the potential to store and transfer charge, as well as sense motion with further optimization and material improvements.