There have been a wide variety of efforts to develop conductive elastomers that satisfy both mechanical stretchability and electrical conductivity, as a response to growing demands on stretchable and wearable devices. This article reviews the important progress in conductive elastomers made in three application fields of stretchable technology: stretchable electronics, stretchable sensors, and stretchable energy harvesters. Diverse combinations of insulating elastomers and non-stretchable conductive materials have been studied to realize optimal conductive elastomers. It is noted that similar material combinations and similar structures have often been employed in different fields of application. In terms of stretchability, cyclic operation, and overall performance, fields such as stretchable conductors and stretchable strain/pressure sensors have achieved great advancement, whereas other fields like stretchable memories and stretchable thermoelectric energy harvesting are in their infancy. It is worth mentioning that there are still obstacles to overcome for the further progress of stretchable technology in the respective fields, which include the simplification of material combination and device structure, securement of reproducibility and reliability, and the establishment of easy fabrication techniques. Through this review article, both the progress and obstacles associated with the respective stretchable technologies will be understood more clearly.

Novel two-dimensional ZnO/Ti₃C₂T_x hybrid photocatalysts with modified surface areas were prepared using a simple calcination technique. The microstructures, crystalline features, and bonding states of the ZnO structure-covered Ti₃C₂T_x MXenes were closely characterized using various tools. The photoluminescence intensity of the hybrid photocatalyst was greatly reduced compared to the pristine ZnO, while its Brunauer-Emmett-Teller (BET) surface area increased by more than 100 times. Under solar light illumination, the photocatalytic degradation efficiency of the hybrid photocatalyst for organic pollutants (MO, RhB) appeared to be three-fold larger as compared to pristine ZnO. The superb photocatalytic performance of the photocatalyst was attributed to several factors, such as ideal band alignment, Schottky barrier formation, and large surface area. Moreover, the ZnO/Ti₃C₂T_x hybrid photocatalyst showed excellent cycling stability. These results suggest that the novel hybrid structure may be a potential candidate for removing organic pollutants in wastewater.

Naturally immiscible PEDOT:PSS and PDMS, which are a typical conducting polymer and an transparent elastomer, respectively, were blended by the support of PDMS-b-PEO. A block copolymer, PDMS-b-PEO, consisting of hydrophobic PDMS backbones and hydrophilic PEO side chains, significantly improved the miscibility of PEDOT:PSS and PDMS. At an optimal PDMS-b-PEO concentration of 30%, a cured PEDOT:PSS:PDMS film was found to be comprised of three-dimensional PDMS networks and a PEDOT:PSS phase filling in between the networks. The optimal blend film exhibited a conductivity comparable to a pure PEDOT:PSS film and a maximum strain to rupture of about 75%. It was also demonstrated that interconnects made of this blend film functioned well irrespective of the substrate and the pattern size, and could reproducibly operate under strains up to 50%. These results indicate that the PEDOT:PSS:PDMS blends could be a practical choice for organic interconnects for future stretchable electronics.

Nanocomposites of PdNPs and ML-Ti ₃ C ₂ T _x MXene are synthesized using a facile two-step process, and it is demonstrated that they can dual-function as a highly sensitive hydrogen sensor and hydrogen storage.