A Soft Sensorized Microfluidic Tubular Actuating Gripper

One of the key challenges in soft robotics today is in providing sensory feedback of an object to a gripper. In this work, a soft microtubular actuator which can not only interact but also sense its environment is reported. As the sensor is enclosed within the same structure as the actuator, the sensor is able to conform well to the whole range of actuating motion and is able to provide accurate sensor readings. As a proof of concept, the sensorized microtubular actuator is deployed as a microgripper. The microgripper demonstrates the ability to grip a variety of objects, including an ant, without damaging it. While similar grippers with integrated sensing elements do exist, the grippers produced in this work have a maximum diameter of 2 mm, which translate to a tenfold reduction in size over the state of the art. This allows the microgripper to conduct in situ monitoring of strain levels or establish if contact with an object has been made. The sensor experiences minimal electrical drift and hysteresis despite repeated loading cycles (1000 cycles). Taken together, these advantages demonstrate the potential of the microgripper for a variety of applications, especially in soft medical robotics.