Human skin is an amazing sensory organ capable of recognizing and processing a huge amount of tactile information.
When the skin comes into contact with an object, mechanoreceptors, thermoreceptors and nociceptors generate electrical signals that are almost instantly transmitted to the brain via the peripheral nervous system. This rapid transmission of information allows the brain to process and interpret tactile signals almost instantaneously.
On the way to creating a perfect artificial sensory system, researchers at the Korea Institute of Engineering and Materials have developed a multimodal tactile perception system. It consists of a vertical stack of four different types of sensors that detect normal force, shear force, dynamic force, and temperature. This stack configuration allows all stimuli to be recognized simultaneously.
The team combined the sensors with a signal processing and transmission module as well as a haptic analysis module. The signal processing module has specialized inputs and outputs for each sensor to perform pre-processing. The signal is then fed into the haptic module for sophisticated analysis.
To make the system practical, the team created the device on a flexible PCB. A custom-built 3D printer was used to fabricate the stretchable, three-dimensional connections between the components. The result is a flexible and relatively thin device that can be applied to a surface like artificial skin.
Looking to the future, the researchers plan to explore ways to endow the device with the ability to perceive the spatial distribution of tactile stimuli. They also intend to explore the possibility of wirelessly transmitting data from the system to external devices.