Microfluidic Janus fibers with dual thermoresponsive behavior for thermoactuation

Thermoresponsive bilayer hydrogels have gained attention due to their fast response time and excellent recovery. A side-by-side capillary-based microfluidic device has been used produce thermoresponsive Janus fibers by photopolymerization of monomer streams. These had one parts consisting in a polymer obtained from oligo(ethylene glycol) acrylate, 2-ethoxyethyl poly(ethylene diacrylate, while the other consisted non-thermoresponsive polymer. The showed reversible coiling uncoiling phenomena with two temperature transitions upon heating (and cooling). unexpected dual thermoresponsiveness was investigated screening wide range parameters including nature photoinitiator comonomers. transition temperatures were tuned 0 80 °C varying comonomer composition, but also concentration crosslinker used. ability these act as thermally-triggered actuators demonstrated performing up four heating–cooling cycles attaching small weight at extremities fiber. results pave way development easily tunable polymer-based fibrous thermoactuators.