Design of Low Pressure Driven Soft Actuators for Soft Gripper

The gripper with a soft pneumatic actuator uses a soft material, unlike the gripper that uses a rigid body, so it is safer and lighter to interact with objects without advanced control technology. Among the soft pneumatic actuators that have been studied, PneuNets actuators have bellows shape, which enable quick operation and complete bending with only small material deformation at low pressure. In this study, we suggested improved form of PneuNets actuators to obtain the performance of the soft actuator that a larger bending angle and larger bending force at a small pressure. An experiment was designed and conducted to measure the bending angle and bending force according to the pressure. As a result, it was confirmed through experiments that the improved model has a maximum bending angle at a pressure of 5 kPa lower than that of the previous model, and a maximum bending force of 1.97 times at the same pressure.2

Ring-pull Type Soft Wearable Robotic Glove for Hand Strength Assistance

This letter proposes and verifies a new method, the ring-pull mechanism, to overcome the disadvantages of existing wearable robotic gloves. By attaching a ring to the metacarpopha-langeal joint of the finger, the ring-pull mechanism supplements the grasping force of the user, while reducing the weight of the entire wearable robotic glove system. Ring-pull mechanism experiments were conducted to determine which finger combinations had the most positive effect on muscle strength assistance, and through this, the Ring-Pull type Soft Glove (RPSG) was developed. The main body of the developed RPSG is composed of single polymer silicon, a soft material, and is driven by tendon-driven actuation. The tendon path is secured through a tube attached to the palm that matches the direction of the flexor digitorum superficialis (FDS). The new type of wearable robotic glove was manufactured with the proposed mechanism, and excellent fit and strength support effects were confirmed. The RPSG increased the subject's grasping force by 25.69% on average, and the %MVIC data analysis demonstrated that the activation of FDS decreased by about 23.51%. As a result, it was confirmed that the user's muscle efficiency was increased due to the muscle support and muscle function improvement provided by the RPSG. © IEEE.FALS

Phytogenic fabrication of iron oxide nanoparticles and evaluation of their in vitro antibacterial and cytotoxic activity

Several metal-based nanoparticles (NPs) have been found to be toxic and are known to exert adverse health outcomes with irreversible side effects. This highlights the need to discover effective, stable, and biocompatible therapeutic components using natural sources. Here, a hexane extract of Nigella sativa seeds was used to synthesize iron oxide NPs (NS-IONPs) embedded with N. sativa phytoconstituents. The extract acted as a reducing agent that restricted the size of the NS-IONPs to 5–6 nm, signifying the potential to be cleared through the renal system. The fabricated NS-IONPs had a prominent effect on pathogenic gram-negative bacteria, E. coli (19.3 mm) and Salmonella typhi (14.2 mm) and lung cancer cells (lowest IC50 of 18.75 µg/mL) mainly by binding to the phospholipid components of the cell membrane. This resulted in cell shrinkage and further inhibited cell growth. Transmission electron microscopy analyses revealed that the mechanisms of cellular NP uptake varied depending on the cell type. Accumulation of NS-IONPs inside the cell increased BAX expression and arrested the cells at the G0/G1 phase, thereby conspicuously extending the G0 phase to initiate necrosis. Thus, these finding suggest that the synthesized NS-IONPs exhibited high antibacterial activity and effective cytotoxicity against cancer cell lines A549 and HCT116 compared to IONPs. The innovation of the current study is that the biogenic fabrication of IONPs is simple and cost effective results in stable nanomaterial, NS-IONPs with potential antibacterial and anticancer activity, which can be explored furthermore for various biomedical applications

Gate-dependent asymmetric transport characteristics in pentacene barristors with graphene electrodes

We investigated the electrical characteristics and the charge transport mechanism of pentacene vertical hetero-structures with graphene electrodes. The devices are composed of vertical stacks of silicon, silicon dioxide, graphene, pentacene, and gold. These vertical heterojunctions exhibited distinct transport characteristics depending on the applied bias direction, which originates from different electrode contacts (graphene and gold contacts) to the pentacene layer. These asymmetric contacts cause a current rectification and current modulation induced by the gate field-dependent bias direction. We observed a change in the charge injection barrier during variable-temperature current-voltage characterization, and we also observed that two distinct charge transport channels (thermionic emission and Poole-Frenkel effect) worked in the junctions, which was dependent on the bias magnitude. © 2016 IOP Publishing Ltd1111sciescopu