High strength and low hysteresis hydrogel based sensing control IoT system for both visible self-monitoring and remote monitoring of massage pressure

Abstract

Abstract Although massage has demonstrated therapeutic effects on stroke, Alzheimer's disease, etc., its efficacy and popularity are still limited due to ambiguity of pressure-therapy relationship and necessity of frequent visits of clinic. In response to this, herein, we proposed a sensing control Internet of Things (IoT) system. Based on Hofmeister effect between polyvinyl alcohol and ammonium phosphate, we developed a piezoresistive hydrogel with the compressive strength of 101.4 MPa and compressive energy loss coefficient of 15.7%. Using this hydrogel as pressure sensing component, we then assembled a wearable sensor that can quantify and transmit the massage pressure with insignificant energy dissipation. By integrating RGB LEDs arrays, the message pressure can be indicated by the color states of LEDs. Furthermore, the wearable sensors and LEDs were connected with a microcontroller (MCU) chip, an IoT chip and a cloud server to form a sensing control IoT system, which can monitor massage pressure both visibly and remotely.