Short Article
When you think of advance robotics you imagine the likes of C3PO or Optimus Prime, a metal construct, researchers are now looking at softer options with the ability to allow handling of delicate objects, and to enable safe collaboration with human users. The researchers at Harvard University and the Wyss Institute for Biologically Inspired Engineering in the US have taken efforts towards soft robotics a step further by demonstrating a robotic system where not only the machine body is soft but the digital logic system to control it is soft too.
“Soft robotics – a field in which compliant rubbers and foams replace the metal gears and grippers of traditional robotics – has only recently begun to receive widespread attention for its ability to allow handling of delicate objects"
Harvard postdoctoral researcher Daniel Preston, who worked alongside Harvard University Professor George Whitesides, on the project and is the lead author of the paper reporting these results also claims when speaking to Physicsworld these “soft” robots are still mainly controlled by electronic computers and hard solenoid valves. This in effect does limit their use in certain medical applications, and also in harsher environments like a chemical spill site.
“We drew on concepts from microfluidics, and ultimately from electronics, to develop a completely soft, pneumatic digital logic system that, when integrated into soft robots, allows memory of past events and simple decision-making abilities.”
The paper describes completely soft pneumatic digital logic gates having a physical scale appropriate for use with current (macroscopic) soft actuators. Each digital logic gate utilizes a single bistable valve—the pneumatic equivalent of a Schmitt trigger—which relies on the snap-through instability of a hemispherical membrane to kink internal tubes and operates with binary high/low input and output pressures. Soft, pneumatic NOT, AND, and OR digital logic gates—which generate known pneumatic outputs as a function of one, or multiple, pneumatic inputs—allow fabrication of digital logic circuits for a set–reset latch, two-bit shift register, leading-edge detector, digital-to-analog converter (DAC), and toggle switch. The DAC and toggle switch, in turn, can control and power a soft actuator (demonstrated using a pneu-net gripper). These macroscale soft digital logic gates are scalable to high volumes of airflow, do not consume power at steady state, and can be reconfigured to achieve multiple functionalities from a single design (including configurations that receive inputs from the environment and from human users). This work represents a step toward a strategy to develop autonomous control—one not involving an electronic interface or hard components—for soft devices.
Research Paper; Digital logic for soft devices Daniel J. Preston, Philipp Rothemund, Haihui Joy Jiang, Markus P. Nemitz, Jeff Rawson, Zhigang Suo, and George M. Whitesides PNAS published ahead of print March 28, 2019 https://doi.org/10.1073/pnas.1820672116
Article sourced from; https://physicsworld.com