Soft Robots
Bio-integrated Robotics Lab
Soft Robots
Soft robotics is an emerging field inspired by the flexibility and adaptability of natural organisms, using soft materials to create machines capable of complex, life-like movements. In nature, creatures like octopuses, worms, and starfish achieve impressive locomotion, manipulation, and adaptation through their soft structures, seamlessly blending strength, agility, and delicacy. The Birl leads in developing design and fabrication techniques for soft robots that replicate these biological capabilities. For instance, by mimicking the gecko's foot—featuring micro-scale foot hairs on a soft backing and leveraging adhesion control through changes in loading conditions—the lab develops robotic pick-and-place solutions for handling objects from micro to larger scales.
Related work 1
S. Song, S. Joshi, J. Paik, CMOS-Inspired Complementary Fluidic Circuits for Soft Robots. Advanced Science 8, 2100924 (2021).
The latest efforts in digital fluidic circuits’ research aim at being electronics-free, light-weight, and compliant controllers for soft robots; however, challenges arise to adjust the fluidic circuit's digital logic operations. Currently, there is no other way to modulate the amplitude or frequency but to structurally redesign the entire fluidic circuitry. This is mainly because there is currently no method to create an analog circuit-like behavior in the digital fluidic circuits using conventional digitized fluidic gates. In this work, a new approach is presented to designing a circuit with digitized fluidic gates that is comparable to an analog circuit capable of actively tuning the circuit's fluidic characteristics, such as pressure gain, amplitude of output, and time response. For the first time, a pressure-controlled oscillator is modeled, designed, and prototyped that not only controls the fluidic oscillation but also modulates its frequency using only a single, quasi-static pressure input. It can also demonstrate the circuit's performance for the control of a soft robotic system by actively modulating the motion of a soft earthworm robot up to twice of crawling speeds. This work has distinct contributions to designing and building intelligent pneumatic controllers toward truly comprehensive soft robotic systems.
Article & Video
Related work 2
S. Song, D.-M. Drotlef, D. Son, A. Koivikko, M. Sitti, Adaptive Self-Sealing Suction-Based Soft Robotic Gripper. Advanced Science 8, 2100641 (2021).
While suction cups prevail as common gripping tools for a wide range of real-world parts and surfaces, they often fail to seal the contact interface when engaging with irregular shapes and textured surfaces. In this work, the authors propose a suction-based soft robotic gripper where suction is created inside a self-sealing, highly conformable, and thin flat elastic membrane contacting a given part surface. Such a soft gripper can self-adapt the size of its effective suction area with respect to the applied load. The elastomeric membrane covering the edge of the soft gripper can develop an air-tight self-sealing with parts even smaller than the gripper diameter. Such gripper shows 4 times higher adhesion than the one without the membrane on various textured surfaces. The two major advantages, underactuated self-adaptability and enhanced suction performance allow the membrane-based suction mechanism to grip various three-dimensional (3D) geometries and delicate parts, such as egg, lime, apple, and even hydrogels without noticeable damage, which can have not been gripped with the previous adhesive microstructures-based and active suction-based soft grippers. The structural and material simplicity of the proposed soft gripper design can have broad use in diverse fields, such as digital manufacturing, robotic manipulation, transfer printing, and medical gripping.