Graphical representation of the sensor and the color changes in response to heat. (Image Credit: DOI: 10.1109/JSEN.2021.3135941)
Liverpool Hope University researchers developed the first robotic sensor capable of imitating a human's response to heat. The robust, Wi-Fi-enabled device measures temperatures variations of 30C per second, identical to someone moving their hand away from a hot area. It could be utilized for space exploration, surgical procedures, and to develop thermo-sensitive soft robots. Plus, it can make robots more proficient in complex environments.
"Although psychologists often state that vision is the main way humans obtain information from the environment when visual perception is impaired, haptic perception is the natural recourse. Even if vision is not impaired, the sense of touch often works in conjunction with visual perception," says lead author Alexander Co Abad.
The team's project adapts the GelSight sensor with a cosmetic pad, making the device accessible for varying fields. Gellight Sensors are commonly deployed on robotic arms to grip objects efficiently. These sensors can process touch information to provide detailed visual 3D topography of a surface. Digital feedback is generated based on what it touches.
The new device uses thermochromic paint, which changes color during temperature changes, allowing it to respond to extreme heat. The paint returns to its original color once the sensor is removed from temperature changes. This device can detect the Haptic Primary Colors, which include force, temperature, and vibration. Such a feature provides the sensor with human pulse recording capabilities.
"Moreover, we demonstrated that we could easily sense temperature using the hue value by using different colors and layers of thermochromic pigments with varying thresholds of temperature on the reflective coating," Abad says, "This thermosensitive visuotactile sensor is the first monolithic elastomer temperature sensor and can be used to infer tactile forces based on the mechanical deformation of the gel."
The sensor rapidly changed color after it was exposed to temperatures higher than 50C. Abad said, "We were able to measure a response time of 643 ms for cold-to-hot and hot-to-cold. The rapid temperature response of our visuotactile sensor is comparable to the less than one second time withdrawal reflex response of the human autonomic system to extreme heat. Our sensor might give robots the ability to react as humans and create thermosensitive soft robots in the near future."
Have a story tip? Message me at: http://twitter.com/Cabe_Atwell