This illustration shows how touching the silicone material in one spot creates a different response than touching it in two spots, allowing it to carry out simple logic functions. Image: North Carolina State University.Inspired by octopuses, researchers have developed a structure that senses, computes and responds without any centralized processing – creating a device that is not quite a robot and not quite a computer, but has characteristics of both. The new technology holds promise for use in a variety of applications, from soft robotics to prosthetic devices.
"We call this 'soft tactile logic', and have developed a series of prototypes demonstrating its ability to make decisions at the material level – where the sensor is receiving input – rather than relying on a centralized, semiconductor-based logic system," says Michael Dickey, co-corresponding author of a paper on the work in Nature Communications and professor of chemical and biomolecular engineering at North Carolina State University.
"Our approach was inspired by octopuses, which have a centralized brain, but also have significant neuronal structures throughout their arms. This raises the possibility that the arms can 'make decisions' based on sensory input, without direct instruction from the brain."
At the core of the soft tactile logic prototypes is a common structure: pigments that change color at different temperatures, mixed into a soft, stretchable silicone polymer. The resulting pigmented silicone contains channels that are filled with metal that is liquid at room temperature, effectively creating a squishy wire nervous system.
Pressing or stretching the silicone deforms the liquid metal, increasing the material’s electrical resistance and thus raising its temperature as current passes through it. The higher temperature triggers a color change in the temperature-sensitive dyes. In other words, the overall structure has a tunable means of sensing touch and strain.
The researchers also developed soft tactile logic prototypes in which this same action – deforming the liquid metal by touch – redistributes electrical energy to other parts of the network. This can cause the material to change color, activate motors or turn on lights. Touching the silicone in one spot can create a different response than touching it in two spots; in this way, the system carries out simple logic functions in response to touch.
"This is a proof of concept that demonstrates a new way of thinking about how we can engineer decision-making into soft materials," Dickey says. "There are living organisms that can make decisions without relying on a rigid centralized processor. Mimicking that paradigm, we've shown materials-based, distributed logic using entirely soft materials."
The researchers are currently exploring ways to make more complex soft circuits, inspired by the sophisticated sensors and actuators found in biological systems.
This story is adapted from material from North Carolina State University, with editorial changes made by Materials Today. The views expressed in this article do not necessarily represent those of Elsevier. Link to original source.