Hong-Soon So

Abstract In this study, a flexible pressure sensor is fabricated using polydimethylsiloxane (PDMS) with a concentric circle pattern (CCP) obtained through a fused deposition modeling (FDM)-type three-dimensional (3D) printer and poly(3,4-ethylenedioxythiophene):poly(styrenesulfonate) (PEDOT:PSS) as the active layer. Through layer-by-layer additive manufacturing, the CCP surface is generated from a thin cone model with a rough surface by the FDM-type 3D printer. A novel compression method is empl

Measurements of physiological parameters such as pulse rate, voice, and motion for precise health care monitoring requires highly sensitive sensors. Flexible strain gauges are useful sensors that can be used in human health care devices. In this study, we propose a crack-based strain gauge fabricated by fused deposition modeling (FDM)-based three-dimensional (3D)-printing. The strain gauge combined a 3D-printed thermoplastic polyurethane layer and a platinum layer as the flexible substrate and c

Flexible pressure sensors have attracted significant attention owing to their broad applicability in wearable electronics and human–machine interfaces. However, it is still challenging to simultaneously achieve a broad sensing range and high linearity. Here, we present a reversed lattice structure (RLS) piezoresistive sensor obtained through a layer-level engineered additive infill structure via conventional fused deposition modeling three-dimensional (3D) printing. The optimized RLS piezoresist

A novel nanocomposite dielectric was developed by embedding polyvinylpyrrolidone (PVP)-encapsulated gold (Au) nanoparticles in the polyvinylidene fluoride (PVDF) polymer matrix. The surface functionalization of Au nanoparticles with PVP facilitates favorable interaction between the particle and polymer phase, enhancing nanoparticle dispersion. To study the effect of entropic interactions on particle dispersion, nanocomposites with two different particle sizes (5 and 20 nm in diameter) were synth

Three-dimensional heterostructured AlGaN/GaN ultraviolet (UV) photodetectors were microfabricated using V-grooved silicon(111) surfaces and metal organic chemical vapor deposition. This novel sensor platform enabled an increase in sensitivity and operation at high temperatures (up to 200°C). More specifically, texturizing the highly conductive 2-D electron gas using the V-groove sensor surfaces, resulted in higher photodetector sensitivity (57.4% increase at room temperature and 139% at 200°C) c

This paper describes a handheld device that uses an all-in-one membrane for continuous mechanical cell lysis and rapid DNA isolation without the assistance of power sources, lysis reagents, and routine centrifugation. This nanowire-decorated multifunctional membrane was fabricated to isolate DNA by selective adsorption to silica surface immediately after disruption of nucleus membranes by ultrasharp tips of nanowires for a rapid cell lysis, and it can be directly assembled with commercial syring

Cost-effective fabrication and rapid packaging of AlGaN/GaN ultraviolet (UV) photodetectors was demonstrated using direct wire bonding between aluminum wires and a GaN surface. The fabricated photodetectors showed stable dark current levels through the highly conductive 2D electron gas (2DEG), which was electrically connected to aluminum bonding wires. At room temperature, the current passing through the 2DEG rapidly increased upon exposure to UV light because of the generated electrons excited

Abstract In this study, an efficient fabrication method to realize a reversible thermo-responsive composite (TRC) and the effect of raster angle were investigated. For the facile fabrication of reversible TRCs, polylactic acid and commercial printing paper were used to generate a polymer/paper bilayer. Using the fused deposition modeling method of three-dimensional printing, three types of TRCs were fabricated and compared depending on the printing angle condition. Above the glass transition tem

Graphene is a 2D honeycomb lattice consisting of a single layer of carbon atoms. Graphene has become one of the most preferred materials for sensor development due to its exceptional electrical, mechanical, and thermal characteristics. Nonetheless, little consideration is given to the production and use of crumpled graphene. Specifically, the crumpled graphene structure is a good choice for enhancing sensors’ sensitivity and structural deformability by reducing interfacial stress, avoiding elect