Soft Microtubule Muscle-Driven 3-Axis Skin-Stretch Haptic Devices

Abstract

In the real world, people heavily rely on haptic or touch to manipulate objects. In emerging systems such as assistive devices, remote surgery, self-driving cars and the guidance of human movements, visual or auditory feedback can be slow, unintuitive and increase the cognitive load. Skin stretch devices (SSDs) that apply tangential force to the skin via a tactor can encode a far richer haptic space, not being limited to force, motion, direction, stiffness, indentation and surface geometry. This paper introduces novel hand-worn hydraulic SSDs that can induce 3-axis tangential forces to the skin via a tactor. The developed SSDs are controlled by new soft microtubule muscles (SMMs) which are driven by hydraulic pressure via custom miniature syringes and DC micromotors. An analytical model is developed to characterize the responses of SMM output in terms of force and elongation. A kinematic model for the motion of the 3-axis SSD is also developed. We evaluate the capability of the tactor head to track circular reference trajectories within different working spaces using an optical tracking system. Experimental results show that the developed SSDs have good durability, high-speed, and can generate omnidirectional shear forces and desired displacement up to 1.8 N and 4.5 mm, respectively. The developed SMMs and SSDs created in this paper will enable new forms of haptic communication to augment human performance during daily activities such as tactile textual language, motion guidance and navigational assistance, remote surgical systems, rehabilitation, education, training, entertainment, or virtual and augmented reality.

Explaining Outcome Differences between Men and Women following Mild Traumatic Brain Injury

“…The distal end of the microtubule is tied in a knot before sealing to the microcoil by an adhesive silicone, while the proximal end is connected to a fluid source via a fluid transmission tube. 7,40 The microtubule is a soft and high strain hollow tube made from silicone elastomer or silicone rubber. The spring coil comes from various materials such as stainless steel, brass, or polymer wires.…”

“…Soft artificial muscles (SAMs) have become an emerging research field in recent years thanks to their promising potential to revolutionize the traditional rigid robotic counterparts. 2,3 With high versatility, flexibility, compliance, and resilience to disturbances, 4,5 the SAMs are ideal substitutes for conventional rigid actuators to develop human-friendly and safe robots, 6 haptic devices, 7 wearable exoskeletons, 8,9 and conformable robotic structures. 10 Abundant ideas in terms of actuation methods and conceptual designs of the SAMs have been proposed, including (i) electrically driven muscles such as dielectric elastomer actuators, 11,12 electroactive polymers, 13 and phase-change materials 14 ; (ii) thermally driven muscles such as shape memory polymers, 15 shape memory alloys, 16 and polymer fibers 17,18 ; and (iii) magnetically driven muscles [19][20][21] and (iv) pressure-driven muscles.…”

“…In addition, it also offers a high strain (at least 250%) and tuneable generated force using a prestretch ratio for the inner silicone tube while maintaining high energy efficiency and wide bandwidth (at least 20 Hz). 7,40 In this article, we introduce a new method of twisting and braiding multiple SMAMs, which can contribute to enhance the muscle elongation and hence contraction force. To demonstrate the effectiveness of the new approach, we constructed different prototypes for new SMAM-based soft muscles using different configurations, including multiple single muscles arranged in nontwisting (or straight), twisting, and braiding variants.…”

Design, Analysis, and Control of a 3-DOF Novel Haptic Device Displaying Stiffness, Texture, Shape, and Shear

“…In telerobotic and minimally invasive surgeries, haptic feedback, especially in the form of stiffness perception along with texture sensations, makes the surgeon feel the tissue properties properly [38]. Knowing tissue stiffness helps to diagnose minor infections up to tumors, lumbar puncture inspection, and so on [39]. Here, texture modality plays an essential role in identifying the initial stage of any infection, where the textural behavior of tissue changes while stiffness may not be affected.…”

Bio‐Inspired Conformable and Helical Soft Fabric Gripper with Variable Stiffness and Touch Sensing

“…Soft robots can be used in many applications such as human-machine interfacing, healthcare, haptics, and assistive technologies. [3][4][5] Soft robots in the form of end effectors can be used for manipulation tasks such as grasping, [6][7][8] locomotion, [2,[9][10][11] surgery, [12][13][14][15][16] or even underwater operations. [17,18] Soft robotic grippers are one of the most extensively investigated research areas in the field of soft robotics.…”