Design of Compliant Systems With Embedded Actuation

Abstract Transmission members, such as gears and linkages, are widely used in mechatronic systems to customize actuator performance. However, in most bioinspired systems, the actuation and transmission members are closely integrated and sometimes indistinguishable from one another. Embedded actuation is advantageous for achieving high strokes and transferring large output forces. This study provides a systematic framework for synthesizing compliant systems with embedded contractile actuators to achieve the desired kinematic objectives. This study builds on the current understanding of the topology of compliant mechanisms, in which constituent members can be functionally classified as load-transferring transmitters and strain-energy-storing constraints. The functional equivalence between the transmitter members and actuators replaces the transmitters in tension with contractile actuators, thus realizing a compliant system with embedded actuation (CoSEA). We present systematic guidelines and best practices for embedding actuators within the topology of a compliant mechanism to improve performance without altering the kinematic behavior. Several examples are presented, including compliant inverting and gripper mechanisms, to validate the efficacy of the proposed framework. In addition, we demonstrate the utility of CoSEAs by conducting design optimization on a shape-morphing system to achieve the desired sinusoidal shape. This framework paves the way for the design of fully autonomous bioinspired systems with embedded actuators and sensors.