University of Tokyo and DNP jointly develop freely stretchable skin display

On February 18, 2018, a research team led by Professor Takao Someya from the Graduate School of Engineering, Graduate School of the University of Tokyo announced: "Skin Display" developed jointly with Dainippon Printing Co., Ltd. This is a system that integrates skin sensing and skin display. It can measure human body signals and display them through intimate contact with the skin. Therefore, personal health management can be easily realized at home. This newly developed "skin display" embeds 16*24 micro-LEDs at equal intervals on a thin, stretchable rubber substrate. The thickness of this rubber substrate is about 1mm, and the repeated shrinkage of the rubber substrate (45% shrinkage rate) will not affect its electrical and mechanical properties. It is said that even if it is directly attached to the skin, it will not hinder the movement of the human body, and it also reduces the burden on people when dressing. Regarding the resolution of the display, the maximum stretched state is 4mm, and its effective area is 64*96mm; the minimum contracted state is 2.4mm, and its effective area is 38*58mm. The size of the micro-LED monomer is 1*0.5mm, the luminous wavelength is 630nm, the driving voltage is 2V, and the maximum power is 13.8mW. The above is a thin, flexible skin display. 16*24 micro-LEDs are embedded at equal intervals on the rubber substrate, with a thickness of about 1mm. Repeated expansion and contraction (45%) will not change the electrical and mechanical characteristics (you can click on the picture to enlarge) show). Another feature of this development is the realization of long-lasting durability of the rubber substrate. When using hard electronic components such as LEDs with shrinkable flexible wiring materials, a lot of stress will occur at the part where the two materials are combined, which is likely to cause failure. This development avoids the concentration of stress and solves the problem of stress. In addition, wiring is flexible, silver wiring technology using screen printing is adopted, and inlay and soldering processes are used for micro LED mounting. These are all existing technologies, which have the potential to improve mass production and holographic projection film reduce costs. sex. The research group is also already developing a skin sensor using nanomesh and wireless modules. Attached directly to the skin, heart waves can be measured. The system integrated with "skin display" can display the measured electrocardiogram in animation. Therefore, from the measurement of human body signals to the display of information, there is no burden on the user, and health management can be carried out naturally. In this study, an animation of the stored ECG was also shown through the rubber substrate display. The display can display the electrocardiogram measured by the skin sensor in the form of animation. By using an integrated system with "skin display", it is light and does not impose a burden on the user because it is only attached to the skin. Regarding the joint research results, they consider mass production within 3 years, so the future research and development directions are: optimization of production equipment structure, improvement of reliability, high concentration of manufacturing process, and expansion of display size.