Design, modelling and experimental validation of bipenniform shape memory alloy-based linear actuator integrable with hydraulic stroke amplification mechanism

TL;DR

This paper presents a novel bipenniform shape memory alloy-based linear actuator with integrated hydraulic stroke amplification, demonstrating high force, reduced weight, and energy efficiency, validated through experiments and benchmarking against industry standards.

Contribution

It introduces a bio-inspired bipenniform SMA actuator with a validated mathematical model, failure mitigation strategies, and superior performance metrics compared to conventional actuators.

Findings

Generated 257 N force at 15 V input

Achieved 67% weight reduction and 32% cost savings

Demonstrated 19% energy savings and comparable dimensions

Abstract

The increasing industrial demand for alternative actuators over conventional electromagnetism-based systems having limited efficiency, bulky size, complex design due to in-built gear-train mechanisms, and high production and amortization costs necessitates the innovation in new actuator development. Integrating bio-inspired design principles into linear actuators could bring forth the next generation of adaptive and energy efficient smart material-based actuation systems. The present study amalgamates the advantages of bipenniform architecture, which generates high force in the given physiological region and a high power-to-weight ratio of shape memory alloy (SMA), into a novel bio-inspired SMA-based linear actuator. A mathematical model of a multi-layered bipenniform configuration-based SMA actuator was developed and validated experimentally. The current research also caters to the incorporation of failure mitigation strategies using design failure mode and effects analysis along with the experimental assessment of the performance of the developed actuator. The system has been benchmarked against an industry-developed stepper motor-driven actuator. It has shown promising results generating an actuation force of 257 N with 15 V input voltage, meeting the acceptable range for actuation operation. It further exhibits about 67% reduction in the weight of the drive mechanism, with 80% lesser component, 32% cost reduction, and 19% energy savings and similar envelope dimensions for assembly compatibility with dampers and louvers for easy onsite deployment. The study introduces SMA coil-based actuator as an advanced design that can be deployed for high force-high stroke applications. The bio-inspired SMA-based linear actuator has applications ranging from building automation controls to lightweight actuation systems for space robotics and medical prosthesis.