The latest achievements of flexible sensors from Tsinghua University are published in Science! Reported by authoritative media such as Xinhua News Agency!
On June 5th, Xinhua News Agency reported under the title "Congratulations to Chinese Scientists!" that Professor Zhang Yihui's research team from the School of Aerospace and Aerospace Science and the Laboratory of Flexible Electronics Technology at Tsinghua University has developed a new electronic skin system with a biomimetic three-dimensional architecture for the first time internationally. It can achieve synchronous decoding and perception of three mechanical signals: pressure, friction, and strain at the physical level. The perception resolution of pressure position is about 0.1 millimeters, close to real skin. This achievement was recently published in the international academic journal Science.
Zhang Yihui introduced that the reason why the skin can sensitively perceive mechanical signals is because there are many high-density and three-dimensional tactile sensory cells inside, which can accurately perceive external stimuli. In the development of electronic skin, it is extremely challenging to be able to simultaneously recognize and decode pressure, friction, and strain signals, and achieve accurate tactile perception.
The team first proposed the concept of electronic skin design with a three-dimensional architecture, and developed a biomimetic three-dimensional electronic skin composed of "epidermis", "dermis" and "subcutaneous tissue", with each part having a texture similar to the corresponding layer in the human skin. Sensors and circuits are distributed in depth within the skin, with some sensors located closer to the skin surface and highly sensitive to external forces. Sensors located deep are more sensitive to skin deformation.
"For example, within a piece of electronic skin the size of our index finger tip, there are 240 metal sensors, each measuring only two to three hundred micrometers, with a spatial distribution similar to the distribution of tactile sensory cells in human skin." Zhang Yihui said that when the electronic skin touches external objects, many sensors inside will work together.The signals collected by sensors undergo a series of transmission and extraction processes, combined with deep learning algorithms, to enable electronic skin to accurately perceive the softness, hardness, and shape of objects.
"Electronic skin is actually a new type of sensor that mimics the perception function of human skin. In the future, it can be installed on the fingertips of medical robots for early diagnosis and treatment, and can also be applied to human skin like a bandage to monitor real-time health data such as blood oxygen and heart rate."Zhang Yihui believes that this biomimetic 3D electronic skin provides a new path for the development and application of electronic skin, and has broad application prospects in industrial robots, biological detection, biomedical, human-computer interaction, and other fields.
Professor Zhang Yihui's research team from the School of Aerospace Science and Technology at Tsinghua University and the Laboratory of Flexible Electronics Technology (Zoomlion) proposed a new electronic skin design concept with a three-dimensional architecture. The three-dimensional distribution of force and strain sensors in the structure imitates the spatial distribution of Merkel cells and Ruffini bodies in human skin, enabling the device to decouple pressure, shear force, and strain from a physical level (Figure 1).Similar to the skin structure, this three-dimensional electronic skin is also composed of "epidermis", "dermis", and "subcutaneous tissue", and the effective modulus of each layer is similar to the corresponding layer in the human skin. The sensors and circuits are mainly located in the "dermis" layer, where the force sensing unit is designed as an eight arm cage structure. The sensors are located in the upper part of the cage structure, closer to the surface of the electronic skin, and therefore highly sensitive to external forces;The strain sensor is located on the arched structure at the bottom of the device, maintaining a certain distance from the sensor on the upper part of the force sensing unit at a vertical height. Therefore, it is only sensitive to tensile strain inside the device and is almost not affected by pressure interference.
Based on this three-dimensional electronic skin architecture and combined with deep machine learning algorithms, the research team has developed an advanced tactile system (Figure 2) that can simultaneously measure the modulus and local principal curvature of an object through touch, demonstrating its application in real scenarios such as determining the freshness of food, and exploring its potential in important fields such as quantitative measurement of physical quantities (such as friction coefficient) and human-computer interaction.
Source: Sensor Expert Network