Design consideration of sustainable self-sufficient energy system using ferroelectric material for wearable healthcare

Abstract

Summary Design of the sustainable self‐sufficient energy generator and storage devices using ferroelectric material were considered for wearable healthcare device. Recently, personal health‐monitoring system is expected to be one of the most important and attractive applications of wearable electronics. It becomes more important for us to develop power generator and storage devices used in monitoring our health condition status on an aging society. The power generator and storage devices are desirable to be embedded into clothes or textile intangibly. In this paper, button type solar cell for power generator and film capacitor on fiber for power storage were considered by using ferroelectric material. The target power consumption for wearable healthcare device is more than 3.6 mW for communication means and sensing ECG, SpO2, temperature, heart rate, and blood pressure that were essential for our health condition monitoring. The target capacity of power storage is more than 150 mAh for 5 days' operation. Clothes are thought to be suitable for embedding sufficient energy system. One proposed circuit that consists of solar cell and film capacitor is considered. The button type solar cell of the four pieces of 20 mm diameter and the film capacitor on fiber are proposed as power generator and storage. The proposed circuit will make it possible to use the healthcare devices more than 5 days without sunshine when we put on clothes of more than 160 g such as thin coat or outerwear. Moreover, the proposed circuit will make it possible to use the devices more than 30 days without sunshine when we put on clothes of more than 960 g such as thick coat or outerwear. As we don't forget to put on clothes that embedded the self‐sufficient energy system, the self‐sufficient system will become useful for sustainable society in the future. Copyright © 2016 John Wiley & Sons, Ltd.

A new approach for body heat energy harvesting

“…We must check a charging state of batteries for these health care devices as monitoring sensors are installed on each place. There are many proposals for energy devices embedded in our clothes, 2,15,16 shoes, 17 and watches. 18 Energy harvesting provides a good solution for the wearable system.…”