FLEX Conference Pass
Highly robust flexible (and stretchable) printed conductors are needed for the manufacturing and development of the next generation of flexible hybrid electronics (FHEs). While silver-based inks lead the market of flexible/stretchable conductive inks due to their high conductivity and printability, they suffer significant drawbacks related to their high cost and inability to tolerate substantial flexing and stretching. Herein, we present ELMNT inks: a line of liquid metal-based highly-stretchable and flexible printable conductive materials that can reliably tolerate strain in excess of 150% while maintaining stable resistance and device functionality.
ELMNT printed stretchable conductors have demonstrated functionality as EKG sensors, analog & digital data transmission cables, wireless power transmitters, stretchable capacitive touch sensors and more. ELMNT inks are printable on thermoplastic polyurethanes (TPUs), thermoplastic elastomers (TPEs), SEBS (styrene-ethylene-butylene-styrene) rubbers, as well as other elastomers via deposition techniques including blade coating, airbrushing, screen printing, aerosol jet printing and extrusion printing. These inks leverage our extensive knowledge of the effects of particle size, suspension rheology, and surface chemistry to tailor the performance to specific applications and processing methods. These tunable parameters include: metal loading, viscosity, thixotropy, recovery time and working time. When mechanically ruptured, EGaIn (eutectic gallium indium) liquid metal core-shell nanoparticles form highly torturous conductive pathways held in place by remaining polymer and metal oxide, allowing for unmatched performance in stretchable and flexible applications due to their conductivity remaining largely independent of strain. The utility of ELMNT inks and the methods behind their unique adaptability will be discussed herein.