High-performance keyboard typing motion driven hybrid nanogenerator

Abstract

Abstract Keyboard is the most common input device in computer and human-machine interface devices. Each keystroke during keyboard typing provides a huge amount of biomechanical energy that can be converted into useful electrical energy. Herein, we propose a high-performance electromagnetic-triboelectric hybrid nanogenerator for harvesting biomechanical energy from keyboard typing motion (KTMEH). Combining the effects of electromagnetic induction and triboelectric contact electrification, the KTMEH can simultaneously scavenge mechanical energy from keystroke motion and deliver a maximum power of 7.04\xa0mW from electromagnetic and 1.8\xa0mW from the triboelectric unit, from a single Typewriter key. The output performances were analyzed for different typing speeds, typing force, and key shapes. For an average typing speed of 4 characters per second (CPS), the KTMEH can scavenge a power of 5.6\xa0mW and 1.5\xa0mW from the electromagnetic and triboelectric unit, respectively. This hybrid configuration and highly miniaturized design enable versatile energy harvesting capability from existing commercial keyboards along with facile installation and durability. From the experimental results, it was found that the harvesting typing motion energy is capable to charge the capacitor and drive commercial electronic loads such as a hygrometer. This work expresses notable advantages of hybrid nanogenerators to develop next-generation self-powered keyboards, self-powered keystroke dynamics monitoring and sensing systems, and security systems with biometric authentication.