The skin is the largest sensory organ of human beings, and the skin area of an adult is about 1.5~2 square meters. It is precisely because of the skin that humans can perceive heat and cold, softness and hardness, pressure, friction, and pain, and the brain will direct the human body to make different responses and actions according to these sensory signals.
Traditional industrial robots and service robots do not have skin-like sensing parts, and can only rely on preset programs to execute some mechanical commands, and the action is full of mechanical sense.
With the development and advancement of flexible materials and micro-nano processing technology, electronic skin came into being. In the future, biomimetic, human-like, interactive, silky and autonomous embodied intelligent robots with electronic skin attached to them will gradually replace traditional robots that rely on preset programs, cannot perceive interactions, and can only mechanically execute commands.
Electronic skin is actually an array of flexible tactile sensors, with piezoresistive, capacitive, piezoelectric and other technical principles.
It is prepared by micro-nano processing technology with flexible materials such as polydimethylsiloxane PDMS and polyvinyl alcohol PVA as substrates, and carbon nanotubes, graphene, conductive polymers and other sensitive materials.
A small piece of electronic skin can integrate many sensing points, which can collect various signals such as pressure and temperature, and then realize functions such as pressure detection, temperature detection, and texture recognition.
It is reported that Hanwei Technology, a well-known sensor company in China, has begun to lay out flexible tactile sensors as early as 2013, and has now built a stable nano-sensitive material system, mastered the four core technologies of flexible piezoresistivity, flexible piezoelectricity, flexible capacitance and flexible sweat, and has core capabilities such as large-area array design, sensitive materials and conductive ink synthesis and preparation, large-area printed electronics batch manufacturing, and has several production lines with an annual output of tens of millions of flexible sensors.
Based on this, Hanwei Technology has formed a multi-variety, multi-range flexible tactile sensor with independent intellectual property rights, and has obtained more than 100 core patents. Taking the flexible pressure sensor as an example, its comprehensive performance has reached the international advanced level.
Ultra-thin and light, with a thickness of less than 0.3mm, which is equivalent to 3 sheets of A4 paper; Super flexible, bent 1 million times, still working normally; Ultra-dense, 100 sensing points/c㎡ can be integrated, with high resolution; Super sensitive, the strength of the feather gently brushed, can also be accurately detected; Ultra-fast, from contact to response, it takes less than 1 millisecond; It can be cut to better fit the end product and meet individual needs.
At present, Hanwei Technology is cooperating with some robot companies to integrate flexible tactile sensors into the fingertips, fingertips, arms and other parts of the robot's dexterous hands. This will be an important perceptual basis for robots to perform complex, fine movements.
According to public reports, the robot prototypes of some manufacturers at home and abroad have been able to realize the functions of grasping eggs, perceiving texture materials, and delivering beverages, and are expected to take the lead in the fields of family services, smart health care, industrial manufacturing, logistics and transportation.
In the future, electronic skin will also be applied to human-computer interaction, medical health, space exploration, bionic robots and other fields, providing a perception basis for VR game control suits, motion capture suits for film and television works, surgical robots, multi-degree-of-freedom bionic prostheses, skin grafting for burn patients, multi-functional dexterous hands for space exploration, and surreal bionic robots. With the continuous development of flexible tactile sensors, more new materials, new structures, new processes, and new applications for electronic skin will continue to emerge.