Powering Wearable Microelectronics

Wearable low power biometric devices and body sensor network systems (BSNs) such as heart, respiration, and activity monitors are popular devices that are predicted to increase tenfold by 2018. This project focused on biomechanical energy harvesting from rib cage expansion using piezoelectric materials and frequency up conversion to power wearable microelectronics.

Summary of Research

Wearable low power biometric devices and body sensor network systems (BSNs) such as heart, respiration, and activity monitors are popular devices that are predicted to increase tenfold by 2018. These devices use batteries which must be recharged or replaced, but it may be possible to use piezoelectric materials to directly harvest energy from biomechanical movement for powering biometric devices for athletes, medical patients, or for physiological monitoring for military personnel.

The goal of this study was to design a harvester utilizing polyvinylidene fluoride (PVDF), lead zirconate titanate (PZT), and piezoelectric fiber composites (PFC) using frequency up conversion to maximize biomechanical energy harvesting from continuous motion of rib cage expansion during respiration. This research investigated the optimal material and spacing of the harvester’s plectra to maximize energy output. A motion simulator was designed to model the biomechanical motion of ribcage expansion. Breathing rates were simulated at 12 and 40 breaths per minute with expansion from 2.5 to 5 cm. Voltage output was measured thirty times for each simulation with plectra spacing of 1.4, 1.6, 3.2, 5, 7.5, and 10 mm. Power generation was calculated. Experimental results indicated frequency up conversion was useful in the harvester design for PFC and PVDF. Optimal configurations produced from 109 to 307 μW (using one piezoelectric beam), indicating the piezoelectric harvester is a viable renewable energy source for low power biometric devices and BSNs.

Leave a Reply

Powering Wearable Microelectronics

Wearable low power biometric devices and body sensor network systems (BSNs) such as heart, respiration, and activity monitors are popular devices that are predicted to increase tenfold by 2018. This project focused on biomechanical energy harvesting from rib cage expansion using piezoelectric materials and frequency up conversion to power wearable microelectronics.

Scroll to top