Researchers at Stanford University have made significant progress in the development of electronic skin, or e-skin, that can mimic the natural process of sensing touch in fingers, toes, and limbs. Led by Zhenan Bao, the team aims to create a flexible and soft prosthetic skin that can transmit electrical signals to the brain, allowing wearers to experience pressure, strain, and changes in temperature. This breakthrough technology could revolutionize prosthetics by providing a realistic sense of touch to users. The e-skin developed by Bao’s team possesses the key attributes necessary for creating a lifelike artificial skin. In natural human skin, mechanical receptors detect sensory information and convert it into electrical pulses that are transmitted to the brain through the nervous system. To replicate this process, the researchers utilized sensors and integrated circuits made from rigid semiconductors, integrated into a flexible polymer dielectric—a thin layer in a semiconductor device that determines signal strength and voltage.
These stretchy and flexible arrays of transistors can convert physical changes into electrical pulses and transmit them to the brain. In an experiment conducted on a rat, the e-skin was connected to the animal’s somatosensory cortex, which processes physical sensations. When the electronic skin was triggered by touch, it sent electronic signals to the rat’s brain, resulting in limb movement. The successful demonstration of this technology in animals paves the way for potential applications in humans, particularly for individuals who have suffered major injuries or have sensory disorders. Although the current e-skin prototype requires a wired connection to an external power source, the researchers envision developing a wireless version in the future.
However, achieving a fully functional e-skin that covers all fingers of a hand and can respond to touch, pressure, and temperature will require further development and refinement. The implications of this research are far-reaching, offering hope to amputees and individuals with sensory impairments. Instead of invasive brain implants, the team proposes placing implants into the peripheral nervous system, reducing the complexity and risks associated with implanting devices directly into the brain. While there is still work to be done, this breakthrough brings us closer to a future where prosthetic limbs can provide a natural sense of touch, greatly enhancing the quality of life for those in need.