A recent innovation at the University of California has used an air-powered computer memory to eliminate one of the main barriers that are the fundamental flaw within pneumatics and electronics. Engineers have made a robot play “Mary Had a Little Lamb” using a piano to demonstrate the breakthrough in the development of Soft Robotics.

The research was supported by the National Science Foundation and was published in the open-access journal PLOS One.

Pneumatic soft robots apply pressurized air to move their soft, rubbery limbs and grippers and are highly preferred to the traditional rigid robots for accomplishing delicate tasks. These robots are also safer for human beings to be around. In the Disney animated movie called Big Hero 6, released in 2014, the healthcare companion robot, Baymax, is a pneumatic robot for a good reason.

Still, the existing systems for managing pneumatic soft robots use electronic valves and computers to maintain the moving elements of the robots. These electronic elements add much cost, size, and power demands to soft robots, restricting their potential.

For the advancement of soft robotics in the future, a team headed by bioengineer doctoral student Shane Hoang with his mentor, William Grover, a bioengineering professor, mechanical engineering professor Konstantinos Karydis and computer science professor Philip Brisk looked back to the past.

“Pneumatic logic” was predated by electronic computers. It offered advanced levels of control in a wide range of devices in the early 1900s, ranging from thermostats and other components of climate control systems to player pianos.

As per pneumatic logic, air, not electricity, passes through circuits or channels, and air pressure is utilized to represent on/off or true/false. These logical elements are represented by 1 and 0 in modern computers to trigger or close electrical charges. The researchers found that they can remove the current electronic memory if they construct a pneumatic “memory” logic for a soft robot.

The researcher’s team employed microfluidic valves instead of electronic transistors in their pneumatic random access memory or RAM. The microfluidic valves were initially designed to check the flow of liquids on microfluidic chips, but they can also control the airflow. Even when detached from the air supply line, the valves remain sealed against a pressure differential, which creates a pressure trap differential that works as memories and keeps robot actuators at balance. The dense ranges of these valves can operate on a complex scale and reduce the costly, bulky, and power-consuming electronic hardware which is generally used to drive and control pneumatic robots.

The researchers built an 8-bit pneumatic RAM chip, which was able to control giant and fast-moving soft robots, after modifying the microfluidic valves to handle massive air flows and integrated it into 3D-pressed rubber hands pair. The pneumatic RAM employs air pressure to represent a value of “0” or “FALSE” with a vacuum representing a value of “1” or TRUE. The soft robotic fingers are stretched when connected to atmospheric pressure and contracted when connected to a vacuum.

Through varying the combinations of vacuum and atmospheric pressure inside the channels of the RAM chip, the team of researchers was able to make the robot play notes, chords, and a whole song called “Mary Had a Little Lamb” on the piano.

In theory, this system can be utilized without electronic hardware to operate other robots and to produce a vacuum merely using a battery-driven pump. The researchers perceive that without positive pressure anywhere in the system, only normal atmospheric air pressure, there’s no chance of accidental overpressurization and violent failure of the robot or its control system. Robots using this technology would be exceptionally safe for sensitive use on or around people, for example, in wearable equipment for motor-impaired infants.