3. Conclusion

In summary, we construct a multistage micro-structured multifunctional ionic skin (MM i-skin) that features high sensitivity, excellent responsiveness (46 ms), great durability, and its superior sensing performance has been vastly improved over previous pressure ionic skin. As a capacitive function ionic skin (C-iskin), it was initially applied to monitor subtle vital physiological signals including breathing, voice recognition, and pulse. As the outstanding contribution of this work, a self-powered wearable health monitoring device using different properties of the same material to achieve two different energy supply modes was devised, that is piezoelectric self-powered ion skin (P-iskin) and thermoelectric self-powered ion skin (T-iskin), aiming at eliminating dependence on external power supply. P-iskin shows great potential for real-time monitoring of human joint activities. Furthermore, the T-iskin based on the low-order thermal energy from the temperature difference between the human body and the environment, which is used for real time monitoring of human joint activities. Therefore, the utilization of own low-order energy proposed in this study provides great reference significance for the construction of self-powered wearable health monitoring devices as well as solving the energy crisis, realizing real-time self-health monitoring and the building of smart medical systems.