Secondary Energy Conversion Devices Based on Cylindrical Liquid Crystalline Elastomer-Assisted Triboelectric Generators

In this study, we demonstrate the preparation of an available secondary energy conversion device that is based on cylindrical liquid crystal elastomers (CLCE) that are equipped with a triboelectric energy generator. Near-infrared energy was changed to mechanical energy and then to electric power. A series of thermally responsive CLCE actuators were fabricated, which show reversible thermal responsive shortening and lengthening actuations. To enhance the near-infrared (NIR) sensitivity, polydopamine (PDA) was coated on the CLCE actuator surface to acquire reversible NIR-responsive actuations. To develop secondary energy conversion devices, a poly(acrylamide)-lithium chloride (PAAm-LiCl) hydrogel was used as a polymeric electrolyte, which was further encapsulated with polydimethylsiloxane (PDMS). The fabricated PDA-coated CLCE actuators were combined with a PAAm-LiCl hydrogel-assembled triboelectric nanogenerator (TENG) to create a photomechanical–electrical secondary energy conversion device. By tapping the PAAm-LiCl hydrogel-assembled TENG, an output voltage of 200 V and a current of 2.5 μA were generated, which lit up 8 LEDs. For CLCE-assisted TENGs, the fabricated secondary energy conversion device generated a voltage of 2.1 V with a current of 90 nA, which lit up a green LED. Based on the results, an available method for fabricating secondary energy conversion devices via predesigned CLCEs was demonstrated successfully, which shows great potential for applications in the field of energy conversion systems.