Tube-Balloon Logic for the Exploration of Fluidic Control Elements
This work addresses the need for accessible and low-cost fluidic control methods for pneumatically driven soft robots, particularly for educational and exploratory purposes, though it is incremental in improving fabrication simplicity.
The paper tackled the problem of complex fabrication in fluidic controllers for soft robots by developing tube-balloon logic circuitry made from straws and balloons, resulting in devices that cost $0.45, take five minutes to fabricate, operate at up to 200 kPa pressure, and oscillate at up to 15 Hz.
The control of pneumatically driven soft robots typically requires electronics. Microcontrollers are connected to power electronics that switch valves and pumps on and off. As a recent alternative, fluidic control methods have been introduced, in which soft digital logic gates permit multiple actuation states to be achieved in soft systems. Such systems have demonstrated autonomous behaviors without the use of electronics. However, fluidic controllers have required complex fabrication processes. To democratize the exploration of fluidic controllers, we developed tube-balloon logic circuitry, which consists of logic gates made from straws and balloons. Each tube-balloon logic device takes a novice five minutes to fabricate and costs $0.45. Tube-balloon logic devices can also operate at pressures of up to 200 kPa and oscillate at frequencies of up to 15 Hz. We configure the tube-balloon logic device as NOT-, NAND-, and NOR-gates and assemble them into a three-ring oscillator to demonstrate a vibrating sieve that separates sugar from rice. Because tube-balloon logic devices are low-cost, easy to fabricate, and their operating principle is simple, they are well suited for exploring fundamental concepts of fluidic control schemes while encouraging design inquiry for pneumatically driven soft robots