# Photoenergy harvesting by ammonium molybdate soft hydrogel drops

## TL;DR

A new biocompatible, flexible photoenergy harvesting system using ammonium molybdate hydrogel drops generates electricity from light and could power IoT devices or aid in tissue repair.

## Contribution

A novel photoenergy harvesting system using ammonium molybdate hydrogel drops that is flexible, biocompatible, and capable of generating electricity from light.

## Key findings

- The hydrogel device generates an open-circuit potential of ~250 mV under excitation light.
- The device maintains output power for milliseconds to thousands of seconds after light exposure ends.
- Scalable PAPH networks can regulate cell growth factors and aid in tissue repair.

## Abstract

Photoenergy harvesting is promising to power Internet-of-Things (IoT) sensors, freeing the limitations of wired power sources or batteries, enabling bio-integrated devices. However, existing photoenergy harvesting systems are restricted to solid or liquid configurations—limiting biocompatibility and space utilization—which makes obtaining flexible, biocompatible, light-harvesting devices a significant challenge. In this paper, inspired by natural ion gradient diffusion in organisms, offering an ion-hydrogel drops-based photoenergy harvesting base on ammonium molybdate. Through the photochemical process of ammonium molybdate, the electric potential of the device is regulated by the altered ion gradient and the redox pairs (\documentclass[12pt]{minimal}
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By using light-responsive molybdate-based ionic hydrogel droplets for photo energy harvesting, can generate a voltage output of ~250 mV.