# Implantable Light‐Powered Human Designer Cells for Electrical Energy Generation

## TL;DR

Scientists created a tiny implantable device using engineered human cells that generate electricity when exposed to light, potentially powering bioelectronic implants.

## Contribution

The novel use of light-activated human designer cells to generate electricity in an implantable biohybrid device is introduced.

## Key findings

- A single solar collection device generates ≈0.4 V under simulated sunlight.
- Multiple devices in series can power a commercial LED.
- The system mimics the eel's electric organ using optogenetically engineered cells.

## Abstract

Herein, an implantable, miniature biohybrid device has been developed that utilizes light‐dependent ion‐gradient formation by genetically engineered human designer cells, expressing light‐activated ion channels and proton pumps to generate electrical potential and deliver electrical energy. These designer cells are cultured in custom‐designed polycarbonate chambers, connected by electrodes and separated from an ion reservoir by a proton‐selective Nafion membrane. Upon illumination, the light‐activated channels and pumps on the designer cells establish a sustained proton gradient across the Nafion membrane, which drives an electrical current in the external circuit. When exposed to simulated ambient sunlight of 3 mW cm−
2 of intensity, a single solar collection device (SCD), containing these designer cells, appropriately sized for subcutaneous implantation in mice, generates an electrical potential of ≈0.4 V. By connecting multiple SCDs in series and increasing the cell suspension volume, the output can be scaled up sufficiently to power a commercial light‐emitting diode. Thus, this study demonstrates the feasibility of a photovoltaic system based on optogenetically engineered mammalian cells for powering bioelectronic implants or wearable devices.

Inspired by the eel's electric organ, a miniature implantable biohybrid device is developed to generate electricity under light activation. The device utilizes a light‐dependent ion gradient formation that induced by genetically engineered human designer cells that express light‐sensitive membrane ion channels and proton pumps, working in synergy with the device to generate electrical potential and deliver electrical energy.