When we think of robots, we usually think of clunky gears, mechanical parts, and jerky movements. But a new generation of robots has tried to break that mold.
Since Czech playwright Karel Čapek first coined the term “robot” in 1920, these machines have come in many shapes and sizes. Robots can be hard, soft, large, microscopic, immobile or human-like, with joints controlled by a range of unconventional motors such as magnetic fields, air or light.
A new six-legged soft robot from a team of engineers at Cornell University has put its own spin on motion, using fluid motors to achieve complex movements. The result: a backpack-carrying bug-like freestanding contraption with a battery-powered Arbotix-M controller and two syringe pumps on top. The syringes pump fluid in and out of the robot’s limbs as it bends along a surface at a rate of 0.05 body lengths per second. The design of the robot was described in detail in a paper published in the journal Advanced Intelligent Systems last week.
The robot was born out of Cornell’s Collective Intelligence Laboratory, which is exploring ways in which robots can think and gather information about the environment with other parts of their bodies outside of a central brain, like an octopus. In doing this, the robot would rely on its version of reflexes, instead of heavy calculation, to calculate what to do next.
[Related: This magnetic robot arm was inspired by octopus tentacles]
To build the robot, the team created six hollow silicone legs. Inside the legs are bellows filled with fluid (pictured inside the accordion) and interconnected tubes arranged in a closed system. The tubes change the viscosity of the fluid flowing in the system, contorting the shape of the legs; The geometry of the stomach structure allows fluid from the syringe to move in and out in specific ways that adjust position and pressure within each leg, causing them to stretch stiffly or deflect into their resting position. Coordinating different, alternating combinations of pressure and position creates a cycling program that causes the legs and the robot to move.
According to a press release, Yoav Matia, a postdoctoral researcher at Cornell and author of the study, “developed a fully descriptive model that could predict the potential intentions of the actuator and predict how different input pressures, geometries, and tube configurations relate and bellow them out. – all with one fluid input.”
Due to the flexibility of these rubber joints, the robot is also able to change its walking or walking style, depending on the landscape or the nature of the obstacles it is crossing. The researchers say that the technology behind these fluid-based motors and nimble limbs can be applied to a range of other applications, such as 3D printed machines and robot arms.