Engineers at the University of California, Riverside have developed pneumatic computer memory to help control the movement of soft robots. The new system addresses one of the biggest challenges in soft robotics, the mismatch between air pressure and electronics.
The study was published in PLOS One..
Pressurized air is used to move the soft, rubbery limbs and grippers of pneumatic soft robots. They are better at performing more delicate tasks than traditional rigid robots. At the same time, they are also safer.
Existing systems used to control pneumatic soft robots rely on electronic valves and computers to maintain the position of moving parts of the robot. However, electronic components increase the cost, size, and power demand of such robots.
The team is organized by Shane Juan, a PhD student in bioengineering, William Glover, a professor of bioengineering, Philip Brisk, a professor of computer science, and Constantinos Calidis, a professor of mechanical engineers. I was led. The team has taken inspiration from the past to advance the field of soft robotics.
“Pneumatic logic” was used in the early 1990s to control a variety of products such as thermostats and climate control systems. It relies on air rather than electricity, and air flows through circuits and channels. Pneumatic pressure is also used to indicate on / off or true / false. On modern computers, this is represented by a code of 1s and 0s, which allows you to control the charge.
Because pneumatic soft robots need to remember and maintain the position of moving parts, researchers have begun to develop a pneumatic logic “memory” that can eliminate the need for electronic memory currently in use.
Creating Pneumatic Random Access Memory
The team created a pneumatic random access memory (RAM) chip using microfluidic valves instead of electronic transistors. Originally designed to control the flow of liquid on a microfluidic chip, the microfluidic valve can also control the flow of air. The valve is sealed against pressure differences, which is true even if the valve is disconnected from the air supply line. The system created a trapped pressure differential that could act as a memory and maintain the state of the robot’s actuators.
By relying on an array of these dense valves, the robot’s movements can perform advanced operations. At the same time, it reduces the need for expensive, bulky, and power-consuming electronic hardware.
The team first modified the microfluidic valve to handle a larger air flow rate. Next, we created an 8-bit pneumatic RAM chip that could control a larger, faster-moving soft robot before incorporating it into a 3D-printed rubber hand.
Pneumatic RAM is used to represent a “0” or FALSE value, depending on atmospheric pressure air, and vacuum is used to represent a “1” or TRUE value. When connected to atmospheric pressure, the fingers of the soft robot stretch, and when connected to vacuum, they contract.
Researchers were able to change the combination of atmospheric pressure and vacuum in the channels of the RAM chip to force the robot to play notes, chords, and ultimately the entire piano song.
According to the team, the system can theoretically be used to operate other robots without the need for electronic hardware. All that is needed to create a vacuum is a battery-powered pump.
There is also no positive pressure in the system, so there is no risk of accidental overpressure or robot and control system failure. This means that these robots are much safer around humans and can be used as wearable devices.