Protocol for in situ 3D printing of liquid metal-hydrogel hybrid for multifunctional soft bioelectronics and devices

3D printing methods allow for the fabrication of liquid metal (LM) wires, but additional encapsulation steps are required to obtain LM-based bioelectronics. Here, we present a protocol for in situ 3D printing of LM-hydrogel hybrids. We describe the steps to prepare gelatin-sodium alginate-potassium chloride (GSP) precursor solution. We then detail procedures for printing gallium (Ga) ink into GSP supporting matrix to form the LM-hydrogel hybrids. This protocol is adaptable to various room temperature LMs and allows printing of diverse LM structures. For complete details on the use and execution of this protocol, please refer to Jiao et al.1 [Display omitted] •Fabricate a support matrix using KCl, sodium alginate, and gelatin•Use an in situ 3D printing method to construct soft bioelectronics and devices•Detailed steps for preparing liquid metal (LM)-hydrogel hybrids Publisher’s note: Undertaking any experimental protocol requires adherence to local institutional guidelines for laboratory safety and ethics. 3D printing methods allow for the fabrication of liquid metal (LM) wires, but additional encapsulation steps are required to obtain LM-based bioelectronics. Here, we present a protocol for in situ 3D printing of LM-hydrogel hybrids. We describe the steps to prepare gelatin-sodium alginate-potassium chloride (GSP) precursor solution. We then detail procedures for printing gallium (Ga) ink into GSP supporting matrix to form the LM-hydrogel hybrids. This protocol is adaptable to various room temperature LMs and allows printing of diverse LM structures.