AsianScientist (Nov. 16, 2018) – A team of researchers in South Korea has developed an artificial touch sensor that mimics the ability of human skin to detect surface information such as shapes, patterns and structures. They published their findings in IEEE/ASME Transactions on Mechatronics.
Not only do humans simultaneously sense multiple features of their environment, such as pressure, temperature, vibration, tension and shear force, but we also detect psychological parameters such as roughness, smoothness, hardness and pain. Detecting precise surface information is a crucial first step towards replicating the psychological sensations of touch.
To tackle this challenge, researchers led by Professor Jang Jae Eun at the Daegu Gyeongbuk Institute of Science and Technology (DGIST) in South Korea developed a device capable of measuring surface textures with high accuracy. The sensor is made from piezoelectric materials—highly sensitive materials that can generate electrical power as a response to applied stress. These materials have similar properties to skin.
The researchers highlighted that their sensor has several advantages over existing artificial sensors. Firstly, it can detect signals through both touch and sliding, which mimics the two ways by which humans sense surface characteristics—by poking a surface or running our fingers over it. Most artificial sensors only rely on a single method.
Secondly, the sensor consists of an array of multiple receptors, thereby allowing sliding speed to be calculated based on the time interval between two receptor signals and the distance between them. Most robotic fingers use just a single receptor and require an external speedometer to gauge sliding speed.
The researchers then tested their sensor by pressing stamps shaped like a square, triangle or dome against the sensor surface. They also added soft material to the sensor to see if it could measure depth, seeking to demonstrate sensing in three dimensions (3D).
The sensor produced different voltages depending on the shape of the stamp. The results showed that the sensor has high spatial resolution and can represent the surface characteristics of certain objects, such as the width and pitch, with high accuracy. However, at present, the sensor cannot distinguish between shapes perfectly in 3D, said the researchers.
In the future, the team hopes that their sensor can be incorporated into electronic devices, such as robots or smartphones, to improve their ability to detect surface textures.
The article can be found at: Shin et al. (2018) Artificial Tactile Sensor Structure For Surface Topography Through Sliding.
———
Source: Daegu Gyeongbuk Institute of Science and Technology; Photo: Pixabay.
Disclaimer: This article does not necessarily reflect the views of AsianScientist or its staff.
