Fabrication of a thin PDMS film with complex liquid metal electrodes embedded and its application as skin sensors

This research work reports an approach for the fabrication of liquid metal patterned thin films. By using this method, very complex liquid metal electrodes can be successfully integrated into a thin PDMS film with a thickness as low as 119 μm. The high resolution of the microelectrode channel is achieved by soft lithography technology. The relatively-thin electrode structure is developed with the assistance of the reversible PC membrane bonding technique that we reported earlier. Femtosecond laser drilling is applied in this work to drill small holes at the channel ends, allowing the air to escape during the filling of liquid metal and making the blind-end liquid metal electrode structure possible. In this work, the fabrication process with some key procedures involved is introduced for developing a microelectrode. Further, a wearable strain sensor is designed with the fabricated microelectrode to show its potential to be used in flexible electronics.