Sung-Hoon Ahn

Rapid Prototyping (RP) technologies provide the ability to fabricate initial prototypes from various model materials. Stratasys Fused Deposition Modeling (FDM) is a typical RP process that can fabricate prototypes out of ABS plastic. To predict the mechanical behavior of FDM parts, it is critical to understand the material properties of the raw FDM process material, and the effect that FDM build parameters have on anisotropic material properties. This paper characterizes the properties of ABS pa

Soft pneumatic actuators and motor-based mechanisms being concomitant with the cumbersome appendages have many challenges to making the independent robotic system with compact and lightweight configuration. Meanwhile, shape memory actuators have shown a promising alternative solution in many engineering applications ranging from artificial muscle to aerospace industry. However, one of the main limitations of such systems is their inherent softness resulting in a small actuation force, which prev

Shape memory alloys (SMAs) are smart materials that are widely used to create intelligent devices because of their high energy density, actuation strain, and biocompatibility characteristics. Given their unique properties, SMAs are found to have significant potential for implementation in many emerging applications in mobile robots, robotic hands, wearable devices, aerospace/automotive components, and biomedical devices. Here, the state-of-the-art of thermal and magnetic SMA actuators in terms o

The one-dimensional deformation of shape memory alloy (SMA) wires and springs can be implemented into different types of functional structures with three-dimensional deformations. These structures can be classified based on the type of structure and how the SMA element has been implemented into the following categories: rigid mechanical joints, semi-rigid flexural hinges, SMA elements externally attached to a soft structure, and embedded into the soft structure. These structures have a wide rang

A soft-bodied robot made of smart soft composite with inchworm-inspired locomotion capable of both two-way linear and turning movement has been proposed, developed, and tested. The robot was divided into three functional parts based on the different functions of the inchworm: the body, the back foot, and the front foot. Shape memory alloy wires were embedded longitudinally in a soft polymer to imitate the longitudinal muscle fibers that control the abdominal contractions of the inchworm during l

This paper describes the development of a biomimetic swimming robot based on the locomotion of a marine turtle. To realize the smooth, soft flapping motions of this type of turtle, a novel actuator was also developed, using a smart soft composite (SSC) structure that can generate bending and twisting motions in a simple, lightweight structure. The SSC structure is a composite consisting of an active component to generate the actuation force, a passive component to determine the twisting angle of

Nastic movements in plants that occur in response to environmental stimuli have inspired many man-made shape-morphing systems. Tendril is an exemplification serving as a parasitic grasping component for the climbing plants by transforming from a straight shape into a coiled configuration via the asymmetric contraction of internal stratiform plant tissues. Inspired by tendrils, this study using a three-dimensional (3D) printing approach developed a class of soft grippers with preprogrammed deform