Joonwon Kim

This paper reports a dramatic reduction of liquid droplet flow resistance by engineering the surfaces into nanomechanical hydrophobic structures that show a contact angle over 175/spl deg/. Flow resistances of droplets on open surfaces as well as in confined microchannels (between surfaces) have been measured with significant reduction of flow resistance (over 99% and over 95%, respectively) compared with a surface of the same material.

Embolization, which is a minimally invasive endovascular treatment, is a safe and effective procedure for treating vascular malformations (e.g., aneurysms). Hydrogel microfibers obtained via spatiotemporally controllable in situ photocrosslinking exhibit great potential for embolizing aneurysms. However, this process is challenging because of the absence of biocompatible and morphologically stable hydrogels and the difficulty in continuously spinning the microfibers via in situ photocrosslinking

Abstract Flexible capacitive‐type touch sensors have significant potential in robotics, foldable displays, and wearable electronics. However, the general parallel‐plate structure of these sensors unintentionally changes initial values and sensitivity in various situations, such as in electromagnetic interference (EMI) and bending. In the present study, a double side EMI‐shielded bending‐insensitive capacitive‐type touch sensor is proposed with a linear response over a wide detection range. The d

We report a simple, efficient microfluidic array system for reliable isolation of cells. A microfluidic array chip, integrated with a size-based cell bandpass filter, provides the unprecedented capability of organizing single cells from a population containing a wide distribution of sizes.

Abstract Multilayered 3D vascular replicas incorporating the complementary advantages of elastomers and hydrogels can serve as a training platform to realistically simulate endovascular intervention, the preferred therapeutic procedure for cardio‐cerebrovascular disease. However, the fabrication process is challenging because of the difficulty in uniformly coating a thin hydrogel layer only on the inner surface of tortuous 3D vascular replicas composed of an elastomer monolayer. This study propo

In this paper, a design method to develop a bending-insensitive capacitive-type touch sensor is reported. To achieve bending-insensitive properties and a shielding effect to block the parasitic capacitance, the sensor is composed of a silver nanowire-based stretchable top electrode layer, a microstructured dielectric layer, and a film-type bottom electrode layer. The stretchability of the top electrode (i.e., tension or compression according to bending) and the pitch of microstructures, which af

Abstract Dip coating has demonstrated great potential as a multimaterial coating method providing additional functions to substrates or producing a freestanding microscopic layer upon removal of the substrate. In dip coating, a liquid layer is applied on a substrate by dipping and withdrawing it from a liquid bath, and then curing the layer in air. Thus, manufacturing uniformly thick layers on serpentine 3D substrates is difficult due to the influence of gravity during the prolonged curing proce