Today, the growing field of soft robotics shows significant growth and investment as it fills the voids of traditional robotics.
Soft robots find themselves grasping everyday objects, moving organs aside in minimally invasive surgeries and flexing as prosthetic limbs.
Soft robotics is centered around the use of elastic materials rather than hard materials. Traditional robotics, comparatively ‘hard robotics,’ involves rigid structures that move by the power of motors. Common soft robots feature empty internal cavities that can be filled, causing motion, grasping or, in advanced cases, both.
A balloon is the simplest example of a soft robot. It sits in its natural resting state until acted upon. If you blow air into the balloon’s empty cavity, the balloon expands to take a new form. This embodies the ‘soft’ aspect of soft robotics; a soft object becomes a robot when it possesses the ability to perform useful work. Imagine you have nine balloons on a table with a book on top, inflating all the balloons lifts the book, resulting in productivity and a functioning soft robot.
From here, the field expands into different methods of enabling motion, or actuation, of the soft robot. In the example of a balloon, pressurized air (pneumatics) is used. Similarly, pressurized water (hydraulics) can fill the elastic cavity. By utilizing heat-sensitive cables, other soft robots mimic tendon and muscle movement seen in animals. Last are dielectric materials, which expand or contract based upon different applied electrical loads. All of these methods have various advantages and disadvantages that make each approach suitable for different applications.
Many systems exercise collaboration between soft and hard robots. Often, a soft robotic component, such as a hand-like gripper, is mounted onto a rigid metallic frame. This collaboration, called robotic symbiosis, is often used in the automated food packing industry. As components roll down a conveyor belt, a rigidly-mounted hard robotic arm is tasked with moving directly above a targeted object. Once in position, the robot’s soft pneumatic ‘hand’ is filled with air, gently grasping the object. The soft end, which acts as the ‘hand’ in this example, complements the hard appendages.
At the University of Rhode Island, third-year ocean engineering doctorate candidate Alexander Yin develops soft robots for undersea environments. Yin enjoys “research for the sake of curiosity.”
After completing his master’s thesis, “Combining Locomotion and Grasping Functionalities in Soft Robotics,” Yin joined Brennan Phillips’ undersea robotics and imaging laboratory at URI to experiment with subsea robots.
“There is an untapped field of soft robotics underwater,” Yin said.
His work focuses on a soft robotic grasping device with multiple six-inch extendable curved ‘fingers,’ ideal for picking up and holding items such as small animals, coral, rocks and solid waste. The internal cavities of Yin’s robot are pumped full of freshwater, a form of hydraulics, which serves as a key advantage.
Caption: A soft robot pressurized with water
“Land robots face increasing self-weight as they increase in size, underwater [soft] robots avoid this weight problem,” he said. “Until we find a material… that enables more complexity, the future will be soft robotic manipulators atop hard robots, [creating] hybrid robots,”
New elastic materials would enable soft robots to reach further without splitting open, hold delicate objects firmly and provide a greater range of motion.
“A soft robot should be 100 percent soft and could be driven over by a car and survive,” Yin said.
Soft robotics is a growing field with a bright future, according to Yin, and he has found the niche community to be both supportive and receptive to his ongoing research.
For more information concerning Yin’s research or soft robotics, Yin encourages students to reach out to [email protected].