An SMA Inchworm-Imitated Robot for Confined Space Inspection.
22 Oct 2021-pp 393-403
TL;DR: In this article, a simplified Ni-Ti shape memory alloy (SMA) based inchworm-imitated robot, aiming to perform the inspection task in narrow/confined spaces.
Abstract: Machines with complicated inner structures are dominating daily life with its diverse functions and high integration. With the increasing disassembling-assembling difficulty, the in-situ inspection and repairing have become important to low down the cost. This paper provided a simplified Ni-Ti shape memory alloy (SMA) based inchworm-imitated robot, aiming to perform the inspection task in narrow/confined spaces. The experiment showed that the robot marching speed reaches 0.57 mm/s under control of 1.5 A current with a voltage of 7 V. The maximum climbing angle on the metal sheet is 6° and the robot could also walk on the board paper, wood, and painted grounds after adding counterweight. The inchworm-imitated robot shows potential for micro-robot walking inside the confined space to perform the in-situ inspection. This gives the possibility of reducing the inner-structure complexity by decreasing the inspection holes, which leads to better utilization and lower sealing difficulty.
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TL;DR: In this article, a complete, unified, one-dimensional constitutive model of shape memory materials is developed and presented in the form of a thermomechanical model for shape memory alloys.
Abstract: The use of the thermoelastic martensitic transformation and its reverse transformation has recently been proposed and demonstrated for several active control ap plications. However, the present constitutive models have lacked several important funda mental concepts that are essential for many of the proposed intelligent material system ap plications such as shape memory hybrid composites.A complete, unified, one-dimensional constitutive model of shape memory materials is developed and presented in this paper. The thermomechanical model formulation herein will investigate important material characteristics involved with the internal phase transformation of shape memory alloys. These characteristics include energy dissipation in the material that governs the damping behavior, stress-strain-temperature relations for pseudoelasticity, and the shape memory effect. Some numerical examples using the model are also presented.
1,222 citations
TL;DR: In this paper, generalized plasticity is adopted as a framework for the development of one-and three-dimensional constitutive models for shape-memory alloys, such as superelasticity, different material behavior in tension and compression, and the single-variant-martensite reorientation process.
622 citations
26 May 2015
TL;DR: This work presents a sheet that can self-fold into a functional 3D robot, actuate immediately for untethered walking and swimming, and subsequently dissolve in liquid, including an acetone-degradable version, which allows the entire robot's body to vanish in a liquid.
Abstract: A miniature robotic device that can fold-up on the spot, accomplish tasks, and disappear by degradation into the environment promises a range of medical applications but has so far been a challenge in engineering This work presents a sheet that can self-fold into a functional 3D robot, actuate immediately for untethered walking and swimming, and subsequently dissolve in liquid The developed sheet weighs 031 g, spans 17 cm square in size, features a cubic neodymium magnet, and can be thermally activated to self-fold Since the robot has asymmetric body balance along the sagittal axis, the robot can walk at a speed of 38 body-length/s being remotely controlled by an alternating external magnetic field We further show that the robot is capable of conducting basic tasks and behaviors, including swimming, delivering/carrying blocks, climbing a slope, and digging The developed models include an acetone-degradable version, which allows the entire robot's body to vanish in a liquid We thus experimentally demonstrate the complete life cycle of our robot: self-folding, actuation, and degrading
229 citations
TL;DR: The Omegabot as discussed by the authors is a crawling robot inspired by an inchworm, which is made of a single part but has two four-bar mechanisms and one spherical six-bar mechanism; the mechanisms are 2-D patterned into a single piece of composite and folded to become a robot body that weighs less than 1 g and that can crawl and steer.
Abstract: This paper proposes three design concepts for developing a crawling robot inspired by an inchworm, called the Omegabot. First, for locomotion, the robot strides by bending its body into an omega shape; anisotropic friction pads enable the robot to move forward using this simple motion. Second, the robot body is made of a single part but has two four-bar mechanisms and one spherical six-bar mechanism; the mechanisms are 2-D patterned into a single piece of composite and folded to become a robot body that weighs less than 1 g and that can crawl and steer. This design does not require the assembly of various mechanisms of the body structure, thereby simplifying the fabrication process. Third, a new concept for using a shape-memory alloy (SMA) coil-spring actuator is proposed; the coil spring is designed to have a large spring index and to work over a large pitch-angle range. This large-index-and-pitch SMA spring actuator cools faster and requires less energy, without compromising the amount of force and displacement that it can produce. Therefore, the frequency and the efficiency of the actuator are improved. A prototype was used to demonstrate that the inchworm-inspired, novel, small-scale, lightweight robot manufactured on a single piece of composite can crawl and steer.
182 citations
TL;DR: A soft-bodied robot made of smart soft composite with inchworm-inspired locomotion capable of both two-way linear and turning movement and achieves a biomimetic inchworm gait is proposed, developed, and tested.
Abstract: 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 locomotion. Each foot of the robot has three segments with different friction coefficients to implement the anchor and sliding movement. Then, utilizing actuation patterns between the body and feet based on the looping gait, the robot achieves a biomimetic inchworm gait. Experiments were conducted to evaluate the robot's locomotive performance for both linear locomotion and turning movement. Results show that the proposed robot's stride length was nearly one third of its body length, with a maximum linear speed of 3.6 mm s(-1), a linear locomotion efficiency of 96.4%, a maximum turning capability of 4.3 degrees per stride, and a turning locomotion efficiency of 39.7%.
173 citations