Direct Writing of Liquid Metal Microheaters for Microvalve Applications

This paper presents the direct writing of liquid metal (LM) based microheaters for microvalve applications based on thermo-responsive polymers. In LM microheaters, rising temperatures (usually beyond 50 °C) can lead to voids formation or electromigration, resulting in failure. To prevent this, multiple layers of liquid metal lines can be printed, increasing their overall height. Experimentally, this method results in more stable and durable microheaters compared to thin, one-time printed wires. These microheaters can withstand temperatures above 160 °C without breakage.