In recent years, many researchers have been focusing on the different novel techniques in designing pneumatic soft actuator that can produce bending motion. This paper presents a novel soft actuator design; a combination of different braided angles of artificial muscle applied on a single chamber soft actuator to produce bending motion. The actuator construction is based on the theory of contraction and extension of artificial muscle. It comprises of fiber-reinforced inside silicone rubber and is capable to create one-sided bending motion. Analysis of nonlinear finite element method is conducted to predict the direction and bending angles of the actuator before a prototype of actuator is fabricated. Based on the results, the developed soft actuator can realize bending motion after standard pressure driving experiment is executed.

Experts have used ultrasound imaging to manually determine follicle count and perform measurements, especially in cases of polycystic ovary syndrome (PCOS). However, due to the laborious and error-prone process of manual diagnosis, researchers have explored and developed medical image processing techniques to help with diagnosing and monitoring PCOS. This study proposes a combination of Otsu’s thresholding with the Chan–Vese method to segment and identify follicles in the ovary with reference to ultrasound images marked by a medical practitioner. Otsu’s thresholding highlights the pixel intensities of the image and creates a binary mask for use with the Chan–Vese method to define the boundary of the follicles. The acquired results were compared between the classical Chan–Vese method and the proposed method. The performances of the methods were evaluated in terms of accuracy, Dice score, Jaccard index and sensitivity. In overall segmentation evaluation, the proposed method showed superior results compared to the classical Chan–Vese method. Among the calculated evaluation metrics, the sensitivity of the proposed method was superior, with an average of 0.74 ± 0.12. Meanwhile, the average sensitivity for the classical Chan–Vese method was 0.54 ± 0.14, which is 20.03% lower than the sensitivity of the proposed method. Moreover, the proposed method showed significantly improved Dice score (p = 0.011), Jaccard index (p = 0.008) and sensitivity (p = 0.0001). This study showed that the combination of Otsu’s thresholding and the Chan–Vese method enhanced the segmentation of ultrasound images.

Towards the development of a safe, small, lightweight and human-friendly finger exoskeleton, device made from high elasticity material driven by pneumatic source; or simply known as soft actuator is currently being paid to attention. The study is to determine the optimum fiber-reinforced elastic soft actuator model to be employed in an exoskeleton for finger rehabilitation. Bending motion anticipated from a 3-D finite element actuator model is verified in the nonlinear finite element software, MARC™. The effectiveness of the proposed model is discussed based on the displacement data obtained from the large strain finite element analysis. Specific geometric properties, material properties, contact and boundary conditions related to the real experimental testing were applied to the analysis. Based on the results, the proposed model shows a good presentation of bending motion at applied pressure of 150 kPa. The behavior of bending motion which is greatly influenced by the angle of the fiber reinforced to the actuator is also discussed.

This paper shows a study on two chambers soft actuator development and its application to an artificial soft actuator fin. Simulations of two chambers actuator are conducted using finite element method software and the bending angles produced are computed. Eleven designs are proposed and compared which differ in separating wall thickness, actuator thickness, fiber location, fiber materials, and rubber materials to analyze the optimal bending angle produced by the actuator. Two actuators are then fabricated and embedded at the ends of soft actuator fin to produce a traveling wave along the soft actuator fin. Soft actuator fin propels like gymnotiform swimmers and shows good linear motion.

GRIP FORCE MEASUREMENT OF SOFT- ACTUATED FINGER EXOSKELETON

In this paper, a robotic fin was idealized with three rays, which are serially connected by thin flexible rubber membranes. Each ray consists a two chamber braided soft actuator operated by pneumatic pressure at the maximum of 20 kPa. The bending of the ray is achieved by alternating the supply of air to the chamber. The soft actuator bends to the right when the left chamber is pressurized and moves to the left when the right chamber is pressurized. The propulsive wave motion along the fin is thus achieved by oscillating the rays at the same frequency but in different phases. The finite element (FE) analysis was conducted in MARC^®, nonlinear FE software, from which the lateral displacements of the rays and the corresponding effect on the membranes were measured. The wave amplitude of the fin was computed from the simulation results. The wave motion of the robotic fin and its corresponding pressure distributions were also observed and presented.