On-Skin Breathable Triboelectric-And-Electromagnetic Liquid-Metal Nanogenerator for Extracting Biomechanical and Electromagnetic Energy and as Whole-Body Epidermal Self-Powered Sensors

On-skin electronics can be conformably deployed on body for health monitoring, assisted living, and human/computer interfaces. However, developing corresponding energy devices is a critical challenge. Herein, a permeable and stretchable multifunctional liquid-metal electronic skin that can generate electricity by recovering ambient electromagnetic pollution (from surrounding electrical appliances) and biomechanical energy (from body movements) is presented for epidermal energy and self-powered sensing applications. To the best of our knowledge, this is the first demonstration that a breathable on-skin device can convert ambient electromagnetic pollution into useful electricity. The device was constructed using two stretchable microfibrous films sandwiching self-organized mesh-like and wrinkled liquid metal that affords electricity via induced electrification (±9.3 V, ±1.7 μA; 60 Hz) and triboelectricity (205.6 V, ±2.3 μA; 4 Hz). Its applicability in powering electronic devices has been demonstrated. Moreover, it can serve as an epidermal self-powered sensor for continuously monitoring whole-body physiological signals and motions of the eyelids, face, throat, chest, and limbs, thus demonstrating its potential to remotely collect clinical and biomechanical information. Finally, it was used as an interface in diverse system-level applications. These results shed light on new directions in on-skin energy and sensing, enabling to usher electronics toward untethered and diversified applications.<br/><br/>Ref.<br/>[1] Ying-Chih Lai*, et al., Advanced Energy Materials, 2021, 202100411. (Selected as VIP paper and front cover)<br/>[2] Ying-Chih Lai*, et al.,Nano Energy, 2022, 95, 107035