Platypus-like robot skin inspired by scientist’s daughter

Researchers have designed a robotic “artificial skin” as unique as the animal the team was inspired by: the platypus. Created by collaborators at Tsinghua University in China and the Institute of Nanoenergy and Nanosystems in Beijing, the dual-sensor system can interpret information not only through direct physical contact, but also by detecting electrostatic changes in the air around it.

The platypus is famous for its many zoological quirks. Over millions of years, this egg-laying mammal has evolved a duck-like bill, webbed feet tipped with tiny venomous claws, and a flat, beaver-like tail. But its notable attributes aren’t all physical: the creature also relies on a highly sophisticated sensory system that can identify both mechanical inputs like touch and electrical variations in its surrounding environment. This added talent helps the platypus hunt for food and evade predators without necessarily needing visual information.

Many people first heard of the platypus as children, including the daughter of Di Wei, a researcher at the Beijing Institute and lead author of a paper published in the journal Scientific progress.

(Related: Platypus Milk Could Save Us From Bacterial Infections.)

“During a conversation, my 9-year-old daughter… told me about a documentary about the platypus that she had watched in the UK. She asked me, ‘Did you know that the platypus… doesn’t rely on its eyes to hunt?’” Wei said in a September 25 profile by TechXplore.

Wei explained that their daughter’s question prompted them to delve further into the platypus’ “remarkable sensory system,” which quickly inspired the development of their team’s new device.

According to Wei, the sensor uses two fundamental principles: contact electrification and electrostatic induction. When the device touches another material, electrons move between their overlapping electron clouds to generate triboelectric electricity. In this way, the sensor receives tactile signals. Meanwhile, electrostatic induction (also known as “teleperception”) allows the artificial skin to detect changes in surrounding electric fields when charged objects are nearby.

(Related: Here’s why Meta is developing robot fingers and skin.)

“Traditional systems often suffer from limitations in sensitivity and accuracy due to weaker charge interactions or surface-level charge detection. Ours improves charge capture by exploiting a structured doped elastomer, which amplifies local electric fields and enhances dielectric polarization,” Wei explains.

Paired with deep learning programming, the team’s multi-receptor skin rapidly identified materials with 99.56% accuracy and detected objects up to 150 mm away. Such capabilities could one day help with environmental modeling of extreme climates, improve human-machine interactions, and potentially power autonomous robotic navigation systems.

Wei’s team now wants to improve the hardware design of their sensor to extend its range and accuracy of detecting the electric field, as well as adapt it to handle unpredictable environments. They also hope to integrate more sensory inputs so that it can interpret complex stimuli with a wider range of perceptual capabilities.