Flexible and Stretchable Strain Sensing Actuator for Wearable Soft Robotic Applications

• Published in: Advanced materials technologies 2016-06, Vol.1 (3), p.n/a
• Main Authors: Yeo, Joo Chuan, Yap, Hong Kai, Xi, Wang, Wang, Zhiping, Yeow, Chen‐Hua, Lim, Chwee Teck
• Format: Article
• Language: English
• Subjects: soft actuator; soft robotics; stretchable strain sensor; wearable electronics
• ISSN: 2365-709X; 2365-709X
• DOI: 10.1002/admt.201600018

Despite the emergence of flexible and stretchable actuators, few possess sensing capabilities. Here, we present a facile method of integrating a flexible pneumatic actuator with stretchable strain sensor to form a soft sensorized actuator. The elastomeric actuator comprises a microchannel connected to a controlled air source to achieve bending. The strain sensor comprises a thin layer of screen‐printed silver nanoparticles on an elastomeric substrate to achieve its stretchability and flexibility while maintaining excellent conductivity at ≈8 Ω sq–1. By printing a mesh network of conductive structures, our strain sensor is able to detect deformations beyond 20% with a high gauge factor beyond 50 000. The integration of a pneumatic soft actuator with our sensing element enables the measurement of the extent of actuator bending. To demonstrate its potential as a rehabilitation sensing actuator, we fit the sensorized actuator in a glove to further analyze finger kinematics. With this, we are able to detect irregular movement patterns in real time and assess finger stiffness or dexterity. A strain sensing actuator comprising silver microstructured mesh network printed on a silicone elastomer is utilized for wearable soft robotic application by Yeo and co‐workers. The crosslinked structures confer robustness to the conductive elastomer with high stretchability and sensitivity. The sensorized actuator can be worn in a glove to measure finger bending and assess finger dexterity and joint stiffness.