Asymmetric Bellow Flexible Pneumatic Actuator for Miniature Robotic Soft Gripper

Abstract

The necessity of the soft gripping devices is increasing day-by-day in medical robotics especially when safe, gentle motions and soft touch are necessary. In this paper, a novel asymmetric bellow flexible pneumatic actuator (AFPA) has been designed and fabricated to construct a miniaturised soft gripper that could be used to grip small objects. The model of AFPA is designed using solid works and its bending motion is simulated in Abaqus software for optimisation and compared with experimental results. The actuator is fabricated using compression molding process that includes micromachining of the molds. Experiments conducted show the bending characteristics of the actuator at different pressures. The actuator shows excellent bending performance and the eccentricity in its design supports increased bending or curling motion up to a certain extent compared to normal bellows without eccentricity. The effects of profile shape and eccentricity on the actuator performance are analysed and the results are presented.

Modeling, Design, and Development of Soft Pneumatic Actuators with Finite Element Method

“…[29] The finite element method (FEM) has been applied to a Manta-like swimming robot, [30] a bending SPA for hand rehabilitation, [17] a miniature soft gripper, [31] and an SPA prototype mimicking the form and function of a human heart. [22] Due to the complexity involved in modeling the extremely high strains, some of these models are based on inflated rubber matrix materials, [17,30,32,33] while other studies have focused solely on fiber-reinforced elastic materials.…”

“…[8] Additionally, although the general hyperelastic behavior of soft materials is well understood, several researchers focus on the linear material response at small strains when capturing the mechanical behavior of SPAs. [14,22] Material laws such as the Mooney-Rivlin [31,35] and Neo-Hookean [34] models are based on linear approximations of the strain invariants, and although they may be accurate in these low-strain regimes, the accuracy of these simplified models is highly limited at higher strains. [36] Instead, a general hyperelastic model should be calibrated across a large range of realistic strains appropriate for the application.…”

Euglenoid-Inspired Giant Shape Change for Highly Deformable Soft Robots

“…Other configurations were examined, including designs with more corrugations for the same length, but these resulted in actuators that did not expand or contract as effectively. Designs with other possible corrugated shapes are presented in [27] but were not fabricated in this study. Fig.…”

Pneumatic Multi-Pocket Elastomer Actuators for Metacarpophalangeal Joint Flexion and Abduction-Adduction

“…However, the finite element method is often used in simulation studies for estimating the response of more complex geometries [20]. The effects of changing different structural parameters, such as wall thickness, have been considered in several previous studies, e.g., by Deimel and Brock [16], Polygerinos et al [20] and Udupa et al [21].…”