Structural Reinforcement Effect of a Flexible Strain Sensor Integrated with Pneumatic Balloon Actuators for Soft Microrobot Fingers.

Satoshi Konishi,Ayano Shimizu,Akiya Hirata,Fuminari Mori

doi:10.3390/mi12040395

Abstract

Motion capture of a robot and tactile sensing for a robot require sensors. Strain sensors are used to detect bending deformation of the robot finger and to sense the force from an object. It is important to introduce sensors in effective combination with actuators without affecting the original performance of the robot. We are interested in the improvement of flexible strain sensors integrated into soft microrobot fingers using a pneumatic balloon actuator (PBA). A strain sensor using a microchannel filled with liquid metal was developed for soft PBAs by considering the compatibility of sensors and actuators. Inflatable deformation generated by PBAs, however, was found to affect sensor characteristics. This paper presents structural reinforcement of a liquid metal-based sensor to solve this problem. Parylene C film was deposited into a microchannel to reinforce its structure against the inflatable deformation caused by a PBA. Parylene C deposition into a microchannel suppressed the interference of inflatable deformation. The proposed method enables the effective combination of soft PBAs and a flexible liquid metal strain sensor for use in microrobot fingers.

Highlights

Robotic systems consist of elemental components including actuators, sensors, and a signal processing controller
This study focuses on improving sensor performance with the aim of integrating a flexible strain sensor with soft pneumatic balloon actuator (PBA), whereas most of previous reports on strain sensors using liquid metals dealt with sensors themselves
This paper describes the integrated design of a liquid metal-based-sensor for the bending motion of PBAs that generates inflatable deformation affecting sensor characteristics by focusing on the geometrical deformation of a microchannel filled with liquid metal

Summary

Introduction

Robotic systems consist of elemental components including actuators, sensors, and a signal processing controller. Robots can acquire information using sensors and drive actuators based on instructions from a controller. Various flexible sensors [1,2,3,4,5] have been developed for wearable sensors, and are attractive for use in soft robotics. A wearable patch as a sweat sensor was developed for diabetes monitoring and therapy [4,5]. These wearable sensors employed flexible materials for improved wearability, and their design is likely to be applicable to soft robotics requiring sensors that maintain the original performance of the robot in the presence of bending and other deformations

Methods

Results

Discussion

Conclusion