Lightweight new sensor

The British New Scientist magazine reports that a sensor-filled transparent plastic sheet that can be used as a medical implant has a very delicate structure that does not cause people's attention, or it can be used as a "sense skin" for prosthetics and robots. Materials scientists at the University of Tokyo, Takao Someya and Martin Kaltenbrunner pointed out that the plastic texture circuit is lighter than feathers, only 1 micron thick, very flexible, can be used as an implanter Placed in the human body, and it is difficult to feel their presence, for example: placed on the back of the hand, or on the lips.

Sakichi Kaohsiung said: "This technology aims to develop a new type of biomedical sensor that does not feel uncomfortable to the wearer. It can also measure body temperature and heart rate without pressure. This is the key to designing sensory touch or temperature for artificial skin. feature."

Previously, scientists had built ultra-thin sensors, including: "Electronic tattoo" patches stuck to the skin, can record brain waves, when the pregnant woman can record the fetal heart rate. But creating thinner, more flexible sensors will cause problems with conventional microchip manufacturing techniques. Normally high-energy plasma can be deposited on the surface of the structure for building circuits, but this method does not work well on soft, skin-like skins. s material.

Sampling Kaohsiung said: "High-energy plasma treatment methods destroy ultra-thin and integrated polymer foils that can form pinholes. Our current approach can avoid this."

The team found a method of depositing a thin aluminum oxide layer on a transparent polymer foil at room temperature, after which it can attach circuit components to oxide substrates, such as transistors made of carbonaceous materials, organic compounds, and touch Sensor or temperature sensor.

Different from traditional semiconductors, this organic material can be processed at room temperature. Current circuits based on organic materials cannot process information as quickly as silicon transistors, but they can adapt well to detectors. The team built a 12 12 array circuit containing an organic touch sensor. The structure weighs only 3 grams per square meter. Super elasticity can be achieved by placing electronic components on the prestretched polymer. When the material was stretched to 2.33 times, its electrical and mechanical properties did not change.

Chris Melhuish, director of experimentation at the Bristol Mechanical Laboratory in the United Kingdom, said that this type of sensor is not capable of independent operation. It requires a power supply. Although it is lighter than a feather, it still needs a similar circuit structure. Current connectivity, which will be the next major design challenge.