Design of Paired Pouch Motors for Robotic Applications

Abstract

Although other soft actuators have been built using smart materials or phasechanging materials, [8][9][10][11] soft pneumatic actuators have generally been the most used type of soft actuator. Pneumatic artificial muscles (PAMs), also called McKibben muscles, consist of a tubular matrix that expands radially and contract longitudinally upon pressurization, and have been widely used due to their large forces and contraction. [12][13][14] Although they can produce forces up to thousands of Newtons at high pressure and are readily available in the market, their range of motion is limited to ≈36.3% of their initial length. Pleated pneumatic artificial muscles have used pleats or fibers to improve the performance of the actuator. [15][16][17] Embedding sheets or fibers allows the fabrication of structure with complex programmed deformations based on origami structures, [18] and contraction ratios of 50% at 100 kPa were achieved using origami-based chambers with an external fiber mesh. [19] Inverse pneumatic artificial muscles capable of contraction ratios of 75% use the opposite principle where a pressure input elongates the actuator and the contraction stroke is done by deflating the actuator. [20] Using a Buckling elastomer under negative pressure has been developed to produce linear actuators capable of contraction ratios in the 40% range, [21,22] and a film containing a structure with repeated zig-zag patterns under vacuum pressure has been able to produce extremely large contraction ratios over 90%. [23] Extremely lightweight actuators made from plastic films have been developed that can produce sufficient forces for a wide range of applications. The first of these is pouch motors where two films are bonded flat and where the lateral expansion of the films upon inflation causes a longitudinal contraction up to 36% of their original lengths. [24] Films have also been used to develop serial pneumatic artificial muscles (sPAMS) where a long tube is restricted at regular intervals and can produce a contraction ratio up to 40% upon inflation. [25] Both actuators function on the same principle as PAMs but made from much lighter and flexible material.A wide range of robotic continuum manipulators have been developed ranging from tendon-driven manipulators installed on moving vehicles and others that behave as an octopus arm, [26,27] pneumatically and vacuum-driven continuum manipulators, [28] vacuum-driven continuum manipulators composed of stackable modules, [29] fluidic elastomer manipulators, [30] continuum actuators combining tendons and PAM actuators for combined position and stiffness control, [31,32] and sPAMs-driven continuum actuators. [25] Other types of robotic arms have used jointed motions using either inflatable joints with a series of single The performance of soft linear actuators will determine the capabilities of future soft robots, and any actuator that can produce larger deformations and forces with a low weight and using lower pressures could potentially become ubiquitous in the field. In this work,...

Cavatappi artificial muscles from drawing, twisting, and coiling polymer tubes

“…Pouch motors are fabricated from bonded films that form an inflatable planar pouch that can be connected in series, forming paired pouch motors. This configuration can develop contractions of 31% with payloads of 10 kg when the pouches are pressurized (9,10). Although paired pouch motors are mentioned here and can be used in soft robotics, these do not appear in Table 1 because nondimensional or specific metrics have not been directly reported in the literature.…”

A Novel Soft Bending Actuator Using Combined Positive and Negative Pressures

“…The use of thin films or textiles instead of rubbers permits the fabrication of very lightweight actuators without necessarily lowering their performance in comparison with polymer-based actuators. Pouch motors with rigid constraints between pouches have been used to produce bending actuators (Niiyama et al, 2015;Oh et al, 2019). Tubes made with inextensible materials with folds have been used to realize smooth or jointed deformations using thermoplastic films (Nishioka et al, 2012(Nishioka et al, , 2017Amase et al, 2015;Sareen et al, 2017).…”

Processing of Self‐Healing Polymers for Soft Robotics

“…[191] Copyright 2018, Wiley-VCH. localized heat sources include impulse sealing [197,198] and heat stamping. [199] These local thermal ablation and welding techniques are fast, precise and repeatable.…”