Remote-controlled droplet chains-based electricity generators

Abstract

Harnessing ambient renewable mechanical energies for achieving carbon-neutrality demands the rational design of materials and architectures which are favorable for both energy collection and conversion simultaneously. However, the direct coupling of energy collection and conversion modules leads to many unwanted problems such as material wearing, the spatial constraint for large-scale integration, and low energy conversion efficiency. Herein, a remote-controlled energy harvesting strategy that cleverly harnesses the unique advantage of diffusive, long-range airflow within a confined capillary channel is developed. The reported device separates the energy collection unit, made of an elastic cavity that directly transforms external mechanical motion to pneumatic motion, from the conversion units, made of encapsulated droplet chains that serve to translate their recurring motion within the capillary channel into electrical output. In contrast to single-drain electrode design for electricity generation from fresh droplets in open spaces, two drain electrodes are designed to collect and release electrostatically induced charges from recurring droplets in the confined channel, respectively, thereby eliminating unwanted charge accumulation on recurring droplets and leading to efficient output performance. The integration of multiple electricity generation units with such a two-drain electrode architecture with a single energy collector improves the design resilience and relaxes the spatial limitation.