Robots made of soft materials have been around for years, with some being used in the automation, manufacturing, and medical industries. While those robots have great potential in many fields, they’re not entirely soft robots and require the use of a computer to be controlled, meaning they use a traditional CPU to function. Scientists from Harvard University have designed a replacement for those hard, inflexible CPUs in the form of a rubber computer that uses rubber, silicon tubing, and pressurized air to replace digital logic gates.
According to lead scientist Daniel J. Preston, “We’re emulating the thought process of an electronic computer, using only soft materials and pneumatic signals, replacing electronics with pressurized air.” Traditional CPUs use digital logic gates- electronic circuits that receive messages as inputs and determine reactions as outputs based on the data being processed. The soft computer works in a similar fashion using a platform similar to microfluidics, only on a larger scale.
The soft computer uses pressurized air that travels through programmed soft valves to perform the types of logic gates needed for complex operations- NOT, AND, and OR, all of which are triggered by different air pressures. For example, if the NOT logic gate uses high pressure, the output will be low pressure, thus using those three logic gates can replicate any behavior found in nearly any electronic computer.
The scientists have used their soft computer in a number of soft robots, including the gripper pictured above, and so far, they have managed to create soft computers with up to 20 logic gates. They plan to continue the development of the soft computer to design robots that will be able to use 100 or even 1,000 logic gates sometime in the near future.