Spiral shape energy harvester with silicone finger bending model using PVDF

Abstract

Energy harvesting through utilizing natural human movement can be considered a certain energy source. This is especially true in the case of wearable devices, where the energy generated by human motion can be proven useful. In this study, the bending motion of a finger has been utilized as an energy source for the proposed wearable device. In a previous study, a compression model was used to demonstrate the circumference change during finger bending. This concept has since been expanded upon to now include a second phalanx in order to demonstrate this bending motion similar to a real human finger. In order to imitate the bone and flesh of a human finger, a 3D printed structure and silicone was used to replicate bone and flesh respectively. To harness the energy from the finger bending motion, spiral shape energy harvesters were fabricated, which are comprised of two main materials - PDMS (Polydimethylsiloxane) and PVDF (Polyvinylidene fluoride). PDMS is used as a flexible substrate for the spiral shape energy harvester, while the PVDF is utilized as a piezoelectric material. The spiral shape energy harvester was then applied on the finger model and studied after a series of conducted bending experiments. In particular, the harvester has been shown to generate electric energy through experiencing strain due to the circumferential change of the silicone during bending. The electrical response was measured according to the induced finger motion and was used to find the optimal energy harvesting condition, including matching impedance. Thus, the feasibility of the proposed spiral shape energy harvesting device has been demonstrated and is expected to be potentially utilized as a wearable device in which a volume change can occur.

Nazanin Minaian

Ph.D. Candidate | Graduate Research Assistant

My research interests include electroactive polymers, flow sensing, energy harvesting, and computer vision.