Adding Stretchability to Flexible Hybrid Electronics by using Metal Gel Interconnects

Abstract: Printed circuit boards have been a defining technology for virtually all electronic devices for the last 60 years. However, there are still some fundamental limitations to integrating rigid boards in diverse spaces. New applications, such as wearables and continuous health monitoring, require circuitry designs which are highly pliable, conformable, and even stretchable. High performance flexible conductors have been in use for years, but stretchable conductors have been much harder to come by. Metal gels, developed by Liquid Wire, are high conductivity materials which are extremely stretchable. Metal gel circuitry can be strained to 100% for thousands of cycles without compromising the electrical signal. Metal gel directly interfaces with components through via structures, which also enable the manufacture of multilayer circuits, thus forming a populated soft circuit board. Alternatively, metal gel can interface with a flexible polyimide board that houses a printed circuit board. This approach is highly modular and enables connections with a vast array of traditional electronic components in a layup that flexes everywhere but also stretches in key zones. Fully packaged electronic assemblies can be integrated with textile garments, automotive or aerospace parts, or placed directly on-body to enable sensing and feedback in an integrated and conformable assembly in areas where high strain, curvature, or motion are unavoidable. Bio: Taylor Neumann joined the Research & Development team at Liquid Wire in 2020. He earned his PhD in Chemical Engineering from North Carolina State University where he studied additive patterning strategies for liquid metals and metal-polymer composites for applications in stretchable and wearable electronics. At Liquid Wire, he focuses on production and characterization of Metal Gel, providing fundamental insight into the mechanical and electrical properties of Metal Gel and working to develop new materials for deployment in Liquid Wire circuitry.