유인상 교수

Feeling temperature and touch The range of receptors in our skin make it possible to sense when we are touching an object and also gives us a general sense of the temperature of that object. Achieving this in an artificial skin-like material has been a challenge because most of the approaches for sensing touch are themselves temperature sensitive. You et al. studied the ion relaxation dynamics in a conductive elastomeric film (see the Perspective by Liu). They show that the ion relaxation time c

With the recent progress made in wearable electronics, devices now require high flexibility and stretchability up to large strain levels (typically larger than 30 % strain). Wearable strain sensors or deformable strain sensors have been gaining increasing research interest because of the rapid development of electronic skins and robotics and because of their biomedical applications. Conventional brittle strain sensors made of metals and piezoresistors are not applicable for such stretchable sens

A new strategy to measure the apex cardiogram with electronic skin technology is presented. An electronic skin apexcardiogram sensor, which can compensate the conventional electrocardiogram for cardiac diagnosis, is demonstrated through a highly sensitive and stretchable strain sensor with gold-nanoparticle composites.

Compliance sensation is a unique feature of the human skin that electronic devices could not mimic via compact and thin form-factor devices. Due to the complex nature of the sensing mechanism, up to now, only high-precision or bulky handheld devices have been used to measure compliance of materials. This also prevents the development of electronic skin that is fully capable of mimicking human skin. Here, we developed a thin sensor that consists of a strain sensor coupled to a pressure sensor and

As industrial needs for healthcare sensors, electronic skin, and flexible/stretchable displays increase, interest in stretchable materials is increasing as well. In recent years, the studies on stretchable materials have spread to various pivot components, such as electrodes, circuits, substrates, semiconductors, dielectric layers, membranes, and active nanocomposite films. The block copolymer (BC) elastomers have been playing considerable role in the development of stretchable materials. Since

Abstract Electronic skin (E‐skin) imitates human skin by converting external stimuli into electrical signals. E‐skin requires high flexibility and a high level of device integration. Unlike conventional E‐skin creation methods, a highly sensitive pressure sensor matrix (100 pixels cm −2 ) made of position‐registered elastic conductive microparticles (MPs) is created. The MPs form a Schottky junction with the bottom electrode and the current through the junction is sensitive to external pressure,

Abstract High‐transconductance stretchable transistors are important for conformable and sensitive sensors for wearables and soft robotics. Remarkably high transconductance, which enables large amplification of signals, has been achieved through the use of organic electrochemical transistors (OECTs). However, the stretchability of such systems has been tempered by the lack of stretchable conductors with high stability in electrolytes, high conductance at high strain (100%), and process compatibi

Despite the advance of on-skin sensors over the last decade, a sensor that solves simultaneously the critical issues for using in everyday life, such as stable performance in various environments, use over a long period of time, and repeated use by easy handling, has not yet been achieved. Here, we introduce an auxetic hygroscopic sensor that simultaneously meets all of the conditions. The auxetic structure with a negative Poisson's ratio matches with deformation of the skin in ankles; hence, a

Abstract Semiconducting ink based on 2D single‐crystal flakes with dangling‐bond‐free surfaces enables the implementation of high‐performance devices on form‐free substrates by cost‐effective and scalable printing processes. However, the lack of solution‐processed p‐type 2D semiconducting inks with high mobility is an obstacle to the development of complementary integrated circuits. Here, a versatile strategy of doping with Br 2 is reported to enhance the hole mobility by orders of magnitude for

Metal oxide films are essential in most electronic devices, yet they are typically deposited at elevated temperatures by using slow, vacuum-based processes. We printed native oxide films over large areas at ambient conditions by moving a molten metal meniscus across a target substrate. The oxide gently separates from the metal through fluid instabilities that occur in the meniscus, leading to uniform films free of liquid residue. The printed oxide has a metallic interlayer that renders the films

In fast and transient somatosensory processing, the relative timing of the selected spikes is more important than the spike frequency because the ensemble of the first spikes in the spike trains encodes the dynamic tactile information. Here, inspired by the functional effectiveness of the selected spikes, we propose an artificial dynamic sensory system based on position-encoded spike spectrum. We use a mixed ion-electron conductor to generate a potential spike signal. We design artificial recept

Human skin is essential for perception, encompassing haptic, thermal, proprioceptive, and pain-sensing functions through ion movement. Additionally, it is mechanically resilient and self-healing for protection. Inspired by these unique properties, researchers have attempted to develop stretchable, self-healing sensors based on ion dynamics. However, most self-healing sensors reported to date suffer from low fracture strength and toughness. In this work, we present an ion-based self-healing elect