# Flexible and Electrically Conductive 3D-Printed Ti3C2Tx MXene–Hydrogel Copolymers for the High-Precision Sensing of Biomechanical Processes

## TL;DR

Researchers developed a flexible, conductive 3D-printed material that can precisely sense biomechanical movements and generate energy from osmosis.

## Contribution

A novel low-weight MXene–hydrogel ink was formulated for DLP 3D printing, enabling high-precision biomechanical sensing and osmotic energy conversion.

## Key findings

- The MXene–hydrogel composites achieved sub-millidegree angle resolution for sensing bending movements.
- The material demonstrated high biocompatibility and mechanical flexibility suitable for medical devices.
- The MXene membranes generated 6.79 Wm−2 of electric power density from osmotic energy conversion.

## Abstract

The application of MXene–polymer composites to wearable and implantable medical devices requires the development of hydrophilic and biocompatible MXene–polymer hydrogel composites with high electromechanical response, flexibility, and durability. Here, we formulate low weight percentage MXene–hydrogel copolymer inks enabling the direct light processing (DLP) of Ti3C2Tx MXene–polyvinyl alcohol (PVA)–polyacrylic acid (PAA)–hydrogel composites. The low wt% MXene–PVA–PAA composites demonstrate high biocompatibility, mechanical flexibility, high sensitivity and high precision for sensing acute bending angles. The sub-millidegree angle resolution of these electromechanical sensors demonstrates their suitability for applications such as the highly precise tracking of joint movements. In addition, the synthesized MXene membranes show promise for applications in osmotic energy conversion, with a harvested electric power density of 6.79 Wm−2.