Surface Potential Modulation in 3D Printed Thermoelectret for Improved Mechanical Energy Harvesting and Physiological Sensing*

Self-powered devices capable of physiological signal detection are the primary demand in the healthcare sector. Recently, PVDF-based sensors have shown potential in human health care monitoring. However, the simultaneous (piezo- and pyro-electric) response of the PVDF-based pressure sensor might generate a lack of accuracy. In addition, the composites-based pressure sensor is cost-intensive and less biocompatible due to toxic parts from inorganic counterparts. It is not advisable in wearable electronics since it has direct contact with the human body.

The present research demonstrates a 3D-printed biopolymer-based thermoelectret (3D-TNG) utilized to operate in self-power mode and can collect energy from mechanical motions and bone-joint motion. Additionally, the 3D-TNG is utilized to monitor coughing and other movements of bone joints, including hinge, condyloid, and ball and socket joints (without any physical contact from the volunteer). Furthermore, the use of 3D-TNG is made to capture the distribution of human foot pressure, which may be used to analyze the physiological signals linked to body balance. The 3D printed self-powered 3D-TNG can monitor precise biomechanical signals, and it envisions the utility in on-spot patient-specific bone fracture due to the ability of instant fabrication of complicated structure by 3D printing technology and charge generation properties of thermoelectret, where PLA-like biopolymer may also be used.