3D Printable and Biocompatible Iongels for Body Sensor Applications

Soft-ionic materials with biocompatibility and 3D printability are needed to develop next-generation devices interface between electronic biological signals. Herein, thermoreversible biocompatible ionic liquid gels or iongels, which can be processed by direct ink writing reported. The iongels designed taking advantage of polyvinyl alcohol/phenol interactions gelify cholinium carboxylate liquids. obtained stable, soft, flexible (Young modulus 14 70 kPa) high conductivity (1.8 × 10–2 S cm–1). Interestingly, they presented properties gel–sol transitions ranging from 85 110 °C, allows the iongel processing via printing material extrusion at temperatures over its transition. These printable integrated into a variety body sensors applications, namely pressure sensors, motion electrodes for electrophysiological recordings. used as sensitivity 0.1 kPa–1, ten times higher than that others similar reported so far; showing ability detect human motion. Furthermore, showed excellent performance in electrocardiography (ECG) recording, presenting good stability time electrocardiographic waves maintained their typical shape even after weeks.