Recent Advances in Biomimetics for the Development of Bio-Inspired Prosthetic Limbs.

Recent advancements in biomimetics have spurred significant innovations in prosthetic limb development by leveraging the intricate designs and mechanisms found in nature. Biomimetics, also known as "nature-inspired engineering", involves studying and emulating biological systems to address complex human challenges. This comprehensive review provides insights into the latest trends in biomimetic prosthetics, focusing on leveraging knowledge from natural biomechanics, sensory feedback mechanisms, and control systems to closely mimic biological appendages.

A study on the fabrication of metal microneedle array electrodes for ECG detection based on low melting point Bi-In-Sn alloys.

This study describes the fabrication and characteristics of microneedle array electrodes (MAEs) using Bismuth-Indium-Tin (Bi-In-Sn) alloys. The MAEs consist of 57 pyramid-shaped needles measuring 340 μm wide and 800 μm high. The fabrication process involved micromolding the alloys in a vacuum environment.

Patterning Techniques in Coplanar Micro/Nano Capacitive Sensors.

Rapid technological advancements have led to increased demands for sensors. Hence, high performance suitable for next-generation technology is required. As sensing technology has numerous applications, various materials and patterning methods are used for sensor fabrication.

Improving the Performance of Polydimethylsiloxane-Based Triboelectric Nanogenerators by Introducing CdS Particles into the Polydimethylsiloxane Layer.

Energy harvesting and power generation technologies hold significant potential for meeting future energy demands and improving environmental sustainability. A triboelectric nanogenerator (TENG), which harnesses energy from the surrounding environment, has garnered significant attention as a promising and sustainable power source applicable in various fields. In this study, we present a technique to improve the triboelectric performance of a PDMS-based TENG by incorporating nanostructured cadmium sulfide (N-CdS).

Nature-Inspired Chiral Structures: Fabrication Methods and Multifaceted Applications.

Diverse chiral structures observed in nature find applications across various domains, including engineering, chemistry, and medicine. Particularly notable is the optical activity inherent in chiral structures, which has emerged prominently in the field of optics. This phenomenon has led to a wide range of applications, encompassing optical components, catalysts, sensors, and therapeutic interventions.

Amplifying the Output of a Triboelectric Nanogenerator Using an Intermediary Layer of Gallium-Based Liquid Metal Particles.

The production of energy has become a major issue in today's world. Triboelectric nanogenerators (TENGs) are promising devices that can harvest mechanical energy and convert it into electrical energy. This study explored the use of Galinstan particles in the production of TENGs, which convert mechanical energy into electrical energy.

Simple Fabrication of Photodetectors Based on MoS Nanoflakes and Ag Nanoparticles.

Low-dimensional transition-metal dichalcogenides (TMDs) have recently emerged as promising materials for electronics and optoelectronics. In particular, photodetectors based on mono- and multilayered molybdenum disulfide (MoS) have received much attention owing to their outstanding properties, such as high sensitivity and responsivity. In this study, photodetectors based on dispersed MoS nanoflakes (NFs) are demonstrated.

Flexible and Stretchable Liquid Metal Electrodes Working at Sub-Zero Temperature and Their Applications.

We investigated characteristics of highly flexible and stretchable electrodes consisting of Galinstan (i.e., a gallium-based liquid metal alloy) under various conditions including sub-zero temperature (i.

Fabrication of a Flexible Photodetector Based on a Liquid Eutectic Gallium Indium.

A fluidic gallium-based liquid metal (LM) is an interesting material for producing flexible and stretchable electronics. A simple and reliable method developed to facilitate the fabrication of a photodetector based on an LM is presented. A large and thin conductive eutectic gallium indium (EGaIn) film can be fabricated with compressed EGaIn microdroplets.

Multiplex lithography for multilevel multiscale architectures and its application to polymer electrolyte membrane fuel cell.

The production of multiscale architectures is of significant interest in materials science, and the integration of those structures could provide a breakthrough for various applications. Here we report a simple yet versatile strategy that allows for the LEGO-like integrations of microscale membranes by quantitatively controlling the oxygen inhibition effects of ultraviolet-curable materials, leading to multilevel multiscale architectures. The spatial control of oxygen concentration induces different curing contrasts in a resin allowing the selective imprinting and bonding at different sides of a membrane, which enables LEGO-like integration together with the multiscale pattern formation.

Microfluidic platforms with monolithically integrated hierarchical apertures for the facile and rapid formation of cargo-carrying vesicles.

We fabricated a simple yet robust microfluidic platform with monolithically integrated hierarchical apertures. This platform showed efficient diffusive mixing of the introduced lipids through approximately 8000 divisions with tiny pores (~5 μm in diameter), resulting in massive, real-time production of various cargo-carrying particles via multi-hydrodynamic focusing.

Replication of flexible polymer membranes with geometry-controllable nano-apertures via a hierarchical mould-based dewetting.

Membranes with nano-apertures are versatile templates that possess a wide range of electronic, optical and biomedical applications. However, such membranes have been limited to silicon-based inorganic materials to utilize standard semiconductor processes. Here we report a new type of flexible and free-standing polymeric membrane with nano-apertures by exploiting high-wettability difference and geometrical reinforcement via multiscale, multilevel architecture.

Multiscale transfer printing into recessed microwells and on curved surfaces via hierarchical perfluoropolyether stamps.

A simple method for the formation of multiscale metal patterns is presented using hierarchical polymeric stamps with perfluoropolyether (PFPE). A dual-scale PFPE structure is made via two-step moulding process under partial photocrosslinking conditions. The hierarchical PFPE stamp enables multiscale transfer printing (MTP) of metal pattern in one step within microwells as well as on curved surfaces.

One-step fabrication of nanowire-grid polarizers using liquid-bridge-mediated nanotransfer molding.

Ag nanowire-grid polarizers (NWGPs) were prepared by a one-step fabrication method, called liquid-bridge-mediated nanotransfer molding (LB-nTM). LB-nTM is a new direct nano-patterning method based on the direct transfer of various materials from a mold to a substrate via liquid layer. We fabricated NWGPs with Ag nanowire arrays (81 nm parallel lines and 119 nm spaces) on 2.

Efficiency improvement of organic solar cells by tuning hole transport layer with germanium oxide.

Improving optical property is critical for optimizing the power conversion efficiency of organic solar cells. In the present research, we show that modification of poly(3,4-ethylenedioxythiophene): poly(styrenesulfonate) (PEDOT:PSS) layer with GeO2 leads to 15% improvement of power conversion efficiency in a polymer solar cells through enhancement of short circuit currents. Modified PEDOT:PSS layer with optimized concentration of GeO2 assists active layer absorbing much light by playing a role of optical spacer.

Epithelial cell patterns on a PDMS polymer surface using a micro plasma structure.

We developed a simple and reproducible epithelial cell-patterning tool on a PDMS (polydimethylsiloxane) polymer surface using a micro plasma structure that did not require chemical or biological treatment. The concept behind this novel approach was based on the fact that cells should easily adhere to the plasma-treated PDMS surface and not the inherent PDMS surface. The micro plasma structure consisted of copper and SU-8 photoresist on a glass substrate.

Producing soft molds of different feature size from a single template.

Molds having physical dimensions different from those on a template, can be obtained from a single template in a predictable way by stretching an elastomeric mold. Stretching results in a reduction of the pitch for line and space patterns. The duty ratio that is the ratio of line width to pitch can also be reduced independently of the change in the pitch.

Top emitting organic light emitting diodes with opaque metal grid electrodes by transfer technique.

The opaque metal grid electrodes are introduced to fabricate top emitting organic light emitting diodes (TOLEDs) through metal transfer technique. To transmit the lights, micrometer-sized patterns of aluminum (Al) were utilized as top cathodes in OLEDs and Al mirrors were also deposited at the other side of transparent substrates to reflect the lights emitted at the bottom sides. Although the only 50% of brightness compared to bottom emitting OLEDs (BOLEDs) could be achieved theoretically, the actual devices showed more than 70% based on the compressive effects during the metal transfer process.

The fabrication of protein nano arrays using 3-dimensional plastic nanopillar patterns.

A plastic nanopillar array was used as the basis for development of a cheap, spatially patterned immobilization method that was applied to nano biochips. A plastic nanopillar array (diameter: 500 nm, height: 1.2 microm) was fabricated using poly(urethane acrylate) (PUA) by simple and fast UV-curable soft lithography.

A microneedle roller for transdermal drug delivery.

Microneedle rollers have been used to treat large areas of skin for cosmetic purposes and to increase skin permeability for drug delivery. In this study, we introduce a polymer microneedle roller fabricated by inclined rotational UV lithography, replicated by micromolding hydrophobic polylactic acid and hydrophilic carboxy-methyl-cellulose. These microneedles created micron-scale holes in human and porcine cadaver skin that permitted entry of acetylsalicylic acid, Trypan blue and nanoparticles measuring 50nm and 200nm in diameter.

The facile fabrication of a wire-grid polarizer by reversal rigiflex printing.

Wire-grid polarizers (WGPs) can be fabricated easily by reversal rigiflex printing. Metal films with gratings were fabricated on a transparent glass substrate by transfer printing with a metal coated rigiflex mold, and the transferred metal gratings were then etched slightly to eliminate the residual layer. As a result, aligned metal wires (70 nm line/space width, 120 nm height) occupying an area of 3.

Gold nanocones fabricated by nanotransfer printing and their application for field emission.

Arrays of gold nanocones have been fabricated by the nanotransfer printing (nTP) method and we have utilized these nanocones for field emission. By the nature of the printing, any shape of metal structure can be fabricated only at desired locations and a step-and-repeat process, which enables large-area fabrication, is possible. We demonstrate step-and-repeat printing with gold nanocone patterns occupying an area of 9 mm × 8 mm.