Design and development of non-magnetic hierarchical actuator powered by shape memory alloy based bipennate muscle

Abstract

Actuators are ubiquitous to generate controlled motion through the application of suitable excitation force or torque to perform various operations in manufacturing and industrial automation. The demands placed on faster, smaller, and efficient actuators drive innovation in actuator development. Shape memory alloy (SMA) based actuators have multiple advantages over conventional actuators, including high power-to-weight ratio. This paper integrates the advantages of pennate muscle of a biological system and the unique properties of SMA to develop SMA-based bipennate actuator. The present study explores and expands on the previous SMA actuators by developing the mathematical model of the new actuator based on the bipennate arrangement of the SMA wires and experimentally validating it. The new actuator is found to deliver at least five times higher actuation forces (up to 150 N) in comparison to the reported SMA-based actuators. The corresponding weight reduction is about 67%. The results from the sensitivity analysis of the mathematical model facilitates customization of the design parameters and understanding critical parameters. This study further introduces an Nth level hierarchical actuator that can be deployed for further amplification of actuation forces. The SMA-based bipennate muscle actuator has broad applications ranging from building automation controls to precise drug delivery systems.

A bio-inspired shape memory alloy-based smart fin system for adaptive thermal management

“…It is observed from the plot that the pattern is matching but the numerical values differ. This difference between experimental and numerical results may be attributed to the fact that some of the material characteristic properties of SMA springs like Modulus of Elasticity, thermal resistivity, etc., used in the numerical simulation have not been experimentally validated and have been used directly from the literature (Chaurasiya et al, 2022; Lagoudas, 2008), which may be slightly different from the actual material properties. Therefore, more accurate results are expected if experimentally established values of all material parameters are used in the study.…”

“…The fin fixed to the heat-dissipating surface is referred to as a fixed fin, while the other fin free to slide above the fixed fin in translatory motion is referred to as a sliding fin. A nature-inspired SMA Pennate actuator achieves this motion (Chaurasiya et al, 2022). The Pennate actuator bears special significance as the placement of SMA springs along the axis of the actuator is identical to the positioning of muscle fibers in the human muscle.…”

“… * Technical Characteristics of FLEXINOL ® Actuator Wires (n.d.). # Chaurasiya et al (2022). ∧ DSC analysis. …”

Tailoring of interface mode with actively controlled SMA spring

“…SMA alloys are a class of smart materials that can change its shape when exposed to higher temperatures, due to changes in the crystal structure of material. [7][8][9] Furthermore, the modulus of the material also depends on martensite volume fraction. Consequently, by controlling the temperature, we can manipulate the stiffness of the material.…”

Design and development of novel rotary actuation system based on shape memory alloy springs driven mechanism arranged in bipennate muscle architecture

“…In the current study, the shape memory alloy (SMA) spring is arranged in a bipennate configuration analogous to the extensor side of the thigh quadriceps femoris. 1,2 The bipennate configuration of SMA wire has been used previously to develop a high-force linear actuator, where six bipennate units of SMA wires were able to develop a force of greater than 100 N. 3 Actuators, on the other hand, are quite important to systems owing to their varied applications. Conventional actuators do have their advantages; however, they have multiple components (prone to wear and tear), are expensive during maintenance, bulky, and suffer from backlashes.…”