Electronic textiles (e-textiles) face challenges in maintaining fabric properties and achieving high electrical conductivity with screen printing and particle-based inkjet printing. While particle-free reactive inks enable high-resolution patterning with sufficient electrical conductivity, their application on cellulose-based fibers is hindered by negatively charged surfaces. This study introduces inkjet-printed e-textiles using reactive silver ink and carbon nanotube ink on poly-L-lysine-coated cotton fabric. Carbon nanotubes establish a conductive network that promotes silver ion reduction, yielding densely packed nanoparticles with enhanced conductivity (1.25 × 10⁵ S m⁻¹). The resulting composite functions as a resistive tactile sensor with high sensitivity (6.02 kPa⁻¹) due to the hierarchical structure of cotton fabric. In addition, the inherent heat resistance of cotton facilitates its high-temperature resistance during heating. In this work, the fabricated e-textiles maintain performance through bending, ironing, and washing, inferring our printing technique as a promising strategy for wearable devices.

Vertically aligned carbon nanotubes exhibit exceptional properties but typically require high temperature (> 700 °C) for growth, thereby complicating low-temperature device integration. Herein, an ice sublimation-based transfer process is proposed for integrating vertically aligned carbon nanotubes into diverse substrates without structural damage. Ambient vapor is condensed under controlled atmospheric conditions to form a thin and uniform ice layer on the acceptor substrate, serving as a temporary adhesive. After transfer, the ice sublimes, enabling the clean release of vertically aligned carbon nanotubes with no residual contaminants while preserving their pristine vertical architecture. Vertically aligned carbon nanotube micropatterns with feature sizes ranging from 10 µm to 1 cm are successfully transferred, achieving yields exceeding 95%. To broaden its practical applications in electronics, micropatterned vertically aligned carbon nanotubes have been successfully transferred onto various substrates like silicon wafers, polymers, and metals, while retaining their electrical, optical, and thermal properties. Furthermore, the transferred vertically aligned carbon nanotubes function as thermal interface materials that reduced smartphone hotspot temperature by 4 °C compared to commercial thermal interface materials, and as infrared absorbers that enhanced sensor sensitivity by up to 3.43-fold. This sublimation-based transfer method expands the potential for direct vertically aligned carbon nanotube integration in next-generation electronic systems.

This paper reports a micro-electro-mechanical (MEM) switch based on carbon nanotube (CNT) array-to-CNT array contact operating at high temperatures. The outstanding interfacial thermal stability of the CNT arrays allowed the successful operation of the switch at 300 °C, under which condition the solid-state transistors or metal-based MEM switches would not be functioning. Our device operated as an n-type MEM switch by forming an air gap based on the intended stiction induced by the wet processes and the recovery after the synthesis of CNTs. Additionally, we investigated the possible degradation in switching behavior and the change in contact resistance at various temperatures. The switch exhibits stable and repetitive operations over 1,000 cycles at 300 °C under hot-switching conditions in nitrogen at atmospheric pressure without a significant change in the switching characteristics.

Currently available hydrogen (H₂) detection methods are fundamentally inefficient because, although leaks are rare, continuous, power-consuming monitoring across large sensor networks is necessary owing to the flammable and explosive nature of H₂. A cost-effective fabrication strategy for chemo-mechanical switches that enables zero-standby-power H₂ detection is presented herein. The switches comprise a palladium (Pd)-based bimorph cantilever structure and are fabricated by tilted metal deposition on water-soluble electrospun nanofiber templates, without the need for conventional photolithography. This approach also permits the use of nonhazardous chemicals, thereby reducing the environmental burden and safety risks during fabrication. The Pd-based cantilevers function as chemo-mechanical H₂ switches; H₂ absorption in the Pd layer induces asymmetric expansion within the bimorph, bending the cantilever, thus closing the gap and establishing electrical contact. The chemo-mechanical H₂ switches are experimentally characterized for various fabrication parameters, and their H₂ detection performances are evaluated in terms of detection threshold, sensitivity, and transient response. The H₂ switches exhibit noise-level currents of ~2.2 pA in the absence of H₂, a low detection limit of 0.3% H₂, short response time of 37.2 s, and high sensitivity exceeding 1.35 × 10⁵.

While there have been remarkable improvements in the fabrication of suspended nanowires, placing a single nanowire at the desired location remains to be a challenging task. In this study, a simple method is proposed to fabricate suspended nanowires at desired locations using an electrospinning process and a designed microstructure. Using electrospun polymer fibers on the designed microstructure as a sacrificial template, various materials are deposited on it, and the electrospun fibers are selectively removed, leaving only nanowires of the deposited material. After the polymer fibers are removed, the remaining metal fibers agglomerate into a single nanowire. Throughout this process, including the removal of the polymer fibers, the samples are not exposed to high temperatures or chemicals, thereby allowing the formation of nanowires without oxidation or contamination. The diameter of the nanowire can be controlled in the electrospinning process, and a suspended Pd nanowire with a minimum diameter of 100 nm is fabricated. Additionally, a suspended single Pd nanowire-based H ₂ gas sensor fabricated using the proposed process exhibits a highly sensitive response to H ₂ gas.