Analysis of Actuator Selection for Low-Cost Bionic Limbs

Abstract

With the continuous advancement of mechatronics, low-cost bionic hands have been widely used in educational experiments and lightweight robotic research. As the core power components, actuators determine the mechanical output, power consumption and overall practical performance of bionic hands. A small mistake made during the choice making of actuators is fatal, which can result in problems such as insufficient gripping force or exceeding cost. This paper first establishes three evaluation criteria for bionic hand actuators: mechanical performance, electrical power requirements and practical application conditions. Then, the operating principles, hardware characteristics and inherent drawbacks of three mainstream actuators which are massively used in this area are elaborated respectively. A comparison is conducted through a table clearly showing the differences between the three types of actuators, and targeted selection suggestions are provided for different application scenarios. This paper finds that servo motors fit low-difficulty rapid teaching prototypes, geared direct current (DC) motors are suitable for stable long-term laboratory experimental platforms, and shape memory alloy (SMA) actuators are limited to lightweight exploratory research due to power consumption and response speed constraints. This research aims to build systematic hardware reference standards for beginners engaged in low-cost bionic hand design, avoiding biased actuator selection caused by ignoring integrated mechanical and electrical constraints.