3D Printing Conductive Hydrogels with Tunable Properties for Soft Robotics and Biosensing

Soft electronics can serve a central role in the development of biosensors, wearable devices, and soft electronics. For these applications, flexible circuits with complex and organic geometries will be necessary. The 3D printing of conductive hydrogels offers a simple manufacturing method for creating such structures and provides opportunities for rapid iteration and modification. Because different applications may call for various hydrogel properties, we demonstrate the ability to tune ink viscosity, hydrogel stiffness, and hydrogel conductivity. These functional hydrogels are based on acrylamide, due its stability and ubiquity, and PEDOT:PSS, a commonly used conductive organic polymer, is embedded to provide conductivity. With thorough characterization, we highlight the advantages of designing conductive hydrogels in this way. Ultimately, we demonstrate the ability to print the components suitable for soft electronics. While this work provides a preliminary demonstration, future steps will focus on applying this method to create biosensors and soft robotics.