Cunjiang Yu (left) and graduate student Hyunseok Shim (right) twist the novel synaptic transistor. Photo: Kelby Hochreither/Penn State.Robotics and wearable devices might soon get a little smarter with the addition of a stretchy, wearable synaptic transistor developed by engineers at Penn State. The transistor works like neurons in the brain that send signals to certain cells while inhibiting others, thereby enhancing and weaking the devices’ memories.
Led by Cunjiang Yu, associate professor of engineering science and mechanics and associate professor of biomedical engineering and of materials science and engineering, the engineers designed the synaptic transistor to be integrated into robots or wearables, using artificial intelligence to optimize its functions. They report their work in a paper in Nature Electronics.
“Mirroring the human brain, robots and wearable devices using the synaptic transistor can use its artificial neurons to ‘learn’ and adapt their behaviors,” Yu said. “For example, if we burn our hand on a stove, it hurts, and we know to avoid touching it next time. The same results will be possible for devices that use the synaptic transistor, as the artificial intelligence is able to ‘learn’ and adapt to its environment.”
According to Yu, the artificial neurons in the device were designed to perform like neurons in the ventral tegmental area, a tiny segment of the human brain located in the uppermost part of the brain stem. Neurons process and transmit information by releasing neurotransmitters at their synapses, typically located at the neuron ends. Excitatory neurotransmitters trigger the activity of other neurons and are associated with enhancing memories, while inhibitory neurotransmitters reduce the activity of other neurons and are associated with weakening memories.
“Unlike all other areas of the brain, neurons in the ventral tegmental area are capable of releasing both excitatory and inhibitory neurotransmitters at the same time,” Yu said. “By designing the synaptic transistor to operate with both synaptic behaviors simultaneously, fewer transistors are needed compared to conventional integrated electronics technology, which simplifies the system architecture and allows the device to conserve energy.”
To model soft, stretchy biological tissues, the researchers used stretchable, bilayer semiconductor polymers to fabricate the device, allowing it to stretch and twist while in use. Conventional transistors, on the other hand, are rigid and will break when deformed.
“The transistor is mechanically deformable and functionally reconfigurable, yet still retains its functions when stretched extensively,” Yu said. “It can attach to a robot or wearable device to serve as their outermost skin.”
This story is adapted from material from Penn State, with editorial changes made by Materials Today. The views expressed in this article do not necessarily represent those of Elsevier. Link to original source.