Exploring Embedded Strain Sensors for Use in Piezoelectric, Planar Soft Robotics

Abstract

Soft robotics is an emerging field related to the use of flexible, non-rigid actuators in robot design. Due to the conformability of such materials, these robots are well-suited for unstructured environments and can achieve safer interactions with humans. However, these same features pose challenges for modeling and control, as robot position can be highly susceptible to environmental factors and exhibit high degrees of freedom. Feedback can be a powerful tool for combatting these disadvantages by lessening reliance on the accuracy of models. An exploration of the use of strain sensors for providing shape information in piezoelectric actuators was undertaken. A linear relationship between strain sensor output and estimated strain was observed through microcontroller data collection. Large variation between different sensors’ outputs may have been a result of differences in bonding across the strained surface. Calibration of the relationship between sensor output and strain estimation was found to be necessary for accurate response. The resulting framework can be employed towards the control of a multi-actuator, piezoelectric inchworm soft robot.