Ha Jin Kim

/V∙s, owing to crystallinity improvement. Rubbery sensors, which include strain, pressure, and temperature sensors, show reliable sensing capabilities and are exploited as smart skins that enable gesture translation for sign language alphabet and haptic sensing for robotics to illustrate one of the applications of the sensors.

There is a growing interest in developing stretchable strain sensors to quantify the large mechanical deformation and strain associated with the activities for a wide range of species, such as humans, machines, and robots. Here, we report a novel stretchable strain sensor entirely in a rubber format by using a solution-processed rubbery semiconductor as the sensing material to achieve high sensitivity, large mechanical strain tolerance, and hysteresis-less and highly linear responses. Specifical

Lubrication of mechanical systems using water instead of conventional oil lubricants is extremely attractive from the view of resource conservation and environmental protection. However, insufficient film thickness of water due to low viscosity and chemical reaction of water with metallic materials have been a great obstacle in utilization of water as an effective lubricant. Herein, the friction between a 440 C stainless steel (SS) ball and a 440 C stainless steel (SS) plate in water lubrication

Wear is a phenomenon that is encountered in most mechanical systems with moving parts. It is directly related to the life and reliability of the system, and hence, wear should be controlled in order to achieve the desired life and performance of the system. Due to the complex nature of wear, understanding of the mechanisms of wear is still lacking. The extent and characteristics of wear depend on the scale of the system which is largely dictated by the load applied between the components in cont

Polymer/lead halide perovskite composites are a promising platform for wearable optoelectronic devices. In particular, one-dimensional nanocomposites are considered core materials for solar energy conversion textiles and optical sensors. Herein, we designed stretchable photodetectors incorporating thin and uniform polymer/perovskite composite nanofibers produced by electrospinning of a polymer/perovskite precursor solution. During the reaction of precursors in the as-spun nanofiber, protruding p

Wearable electronics demonstrate great potential for a wide range of applications, including electronic skin, implantable bio-medical devices, and health monitoring sensors. Such applications require highly stretchable and durable electrodes for adequate reliability and superior performance. Although extensive works on intrinsically stretchable electrodes have been reported, obtaining both mechanical integrity and electrical conductivity remains challenging owing to a trade-off effect. In additi

As attractive photoactive materials, metal halide perovskites demonstrate outstanding performance in a wide range of optoelectronic applications. Among the various compositions studied, mixed-halide perovskites have a finely tunable band gap that renders them desirable for targeted applications. Despite their advantages, photoinduced halide segregation often deters the photoelectric stability of the materials. Herein, we adopt a strategy of post-treating the perovskite surface with an organic sp

Abstract Lead halide perovskite is one of the attractive functional materials owing to its outstanding opto‐electronic properties, which have been addressed in numerous studies. This study aims to clarify the link between the growth pattern and the charge carrier related properties for the highly oriented perovskite film along the [100] direction. For this purpose, a CH 3 NH 3 PbI 3 thin film mainly grown along the [100] direction was fabricated and subjected to spectroscopic analysis to underst

Semiconducting polymers are considered essential materials because of the dramatically increasing demand for deformable electronic and energy devices. However, an improvement in both the electrical conductivity and mechanical stretchability of these polymers has been challenging. In this study, we designed a composite material comprising Li-complexed poly(3-hexylthiophene) nanofibrils (Li-P3HT) and poly(styrene-b-butadiene-b-styrene) (SBS) as the conductive and stretchable active layers of elect