Fast Actuating Multi-helically Heated Twisted and Coiled Polymer Actuator

Jiali Bao1; Chengyeh Ho1; Haojing Xu2; Yujia Wu3; Bo Yan2; Yanji Lin2; Kezhou Chen4; Jing Xu1

2023

10.1109/LRA.2023.3240336

IEEE Robotics and Automation Letters   Impact Factor & Quartile

2377-3774

2377-3766

The twisted and coiled polymer actuator (TCPA), promisingly used in wearable robots, soft exoskeletons and prosthesis, retains the advantages of convenience, high energy density, scalable stroke and hysteresis-free. However, as a thermal actuator, its dynamic response is still rather low, not only because of its convection improvable long cooling time, but also due to its long heating time. PID control is used to shorten TCPAs' rising time. However, this improvement is restricted by the upper limit of the heater temperature and has not substantially improve the poor heat conduction between nylon and heater. In addition, the high working current is also an important defect limiting TCPAs' application. In this work, we have revealed that the practical thermoelectric model of a TCPA obeys the law of heat transfer with Dirichlet condition. Under the consideration that TCPAs with symmetrical Dirichlet condition can effectively improve their heating performance, we have proposed a multi-helically heated twisted and coiled polymer actuator (MHTCPA). Through physical and simulated experiments, we verify that the MHTCPA has better actuating performance, requires less current, and that the symmetry of boundary conditions is the principal factor to improve the heating performance. Given the same power limit, the MHTCPA has a 20% smaller time constant, adopting a 24% smaller current to reach a 15% higher temperature and takes 50% less time to finish actuation. With the help of closed-loop control method, the actuation of the MHTCPA takes 83% less time compared previous TCPA. For the mechanical properties, the MHTCPA is still hysteresis-free but 25.8% stronger in lifting a 100-g weight.

Soft Sensors and Actuators Modeling, Control, and Learning for Soft Robots Soft Robot Materials and Design

English

Others

2-s2.0-85148452093

IEEE

1.State Key Laboratory of Tribology, Department of Mechanical Engineering, Beijing Key Laboratory of Precision/Ultra-Precision Manufacturing Equipment Control, Tsinghua University, Beijing, China
2.Department of Mechanical Engineering, Tsinghua University, Beijing, China
3.Department of Energy and Power Engineering, Tsinghua University, Beijing, China
4.Department of Mechanical and Energy Engineering, Southern University of Science and Technology, Shenzhen, China

Jiali Bao,Chengyeh Ho,Haojing Xu,et al. Fast Actuating Multi-helically Heated Twisted and Coiled Polymer Actuator[J]. IEEE Robotics and Automation Letters,2023,PP(99):1-8.

Jiali Bao.,Chengyeh Ho.,Haojing Xu.,Yujia Wu.,Bo Yan.,...&Jing Xu.(2023).Fast Actuating Multi-helically Heated Twisted and Coiled Polymer Actuator.IEEE Robotics and Automation Letters,PP(99),1-8.

Jiali Bao,et al."Fast Actuating Multi-helically Heated Twisted and Coiled Polymer Actuator".IEEE Robotics and Automation Letters PP.99(2023):1-8.