Papermaking is one of the four major inventions in China. Paper is the wisdom of the ancient Chinese working people through long-term experience accumulation. It consists of natural or man-made cellulose fibers and additives, which plays a role in recording and disseminating information in people's daily lives. Important role. So, is it possible to make paper serve future wearable smart devices and human interface applications? Recently, the team of the Associate Researcher of the Shenzhen Institute of Advanced Technology of the Chinese Academy of Sciences, and the team of the University of California at Davis, Pan Tingrui, teamed up to bring the touch sensing function to the paper by introducing the electronic sensing mechanism into the paper. The related paper "Integrated Electronic Sensing Paper" was published in the international academic journal "Advanced Functional Materials" (All-in-One Iontronic Sensing Paper. Adv. Funct. Mater. 2019, 1807343), article One author is a Ph.D. student, Li Sen, Chang Yi and Pan Tingrui, who are co-authors.
In recent years, smart packaging, smart wearable electronic devices and flexible human-machine interfaces have attracted more and more attention, and this field has become a hot spot in scientific research. The pursuit of high sensitivity, low cost, 3D structural and surface adaptability has become an important trend. As a soft, foldable, printable, cleavable, disposable, and degradable material, paper is a low-cost, long-term flexible platform for chemical and biosensing. For example, pH test strips, blood glucose test strips, early pregnancy test strips, paper-based organic gas sensors, DNA and protein sensors are widely used biochemical sensors. The previously reported pressure sensitive papers and pressure sensors made therefrom are based primarily on three existing sensing mechanisms, namely resistive, capacitive and triboelectric. They have problems such as complicated preparation methods, low response linearity and response speed. In addition, the paper-based sensors currently reported fail to take full advantage of the printable, shearable, and foldable characteristics of the paper.
The integrated electronic sensor paper developed by the team made up for the above shortcomings. Based on the flexible ion-off sensing mechanism, the research team proposed an electronic sensor paper (ISP) as an integrated flexible sensing platform that contains both ion and electrode regions and has direct printability, custom cutability and three-dimensional Folding. The ISP can construct the pressure sensor device in the form of a two-dimensional plane or three-dimensional origami simply by paper-specific operations such as printing, cutting, folding, and gluing. In addition, the sensitivity of the ISP device is 10nF/kPa/cm2, which is at least several thousand times that of the current capacitive sensor, with a resolution of 6.25Pa, fast mechanical response time of one millisecond and high response linearity (R2> 0.996). . In addition, the team also established a theoretical model for the ISP device, deriving and verifying that the model can reasonably explain the ISP capacitance-pressure characteristics.
Thanks to the unique performance of paper, ISP can be cut into any shape and seamlessly integrated with objects or their packaging to detect weight changes; ISP can also be folded to build smart 3D origami with electronic interface, for example with high volume Controlled high-sensitivity paper piano and wearable origami bracelet for continuous monitoring of pulse waveforms; in addition, with a sandwich structure, ISP can construct a 16×16 pressure sensing array that can track and record Chinese calligraphy. Handwriting and pressure distribution.
This work provides a simple and low-cost method for paper sensing platforms. ISP demonstrates the concept of original smart paper from the principle of electronic sensing, with significant sensing advantages in human-machine interface, smart packaging. Health wearable has broad application prospects.
The project was supported by the National Natural Science Foundation of China, the Ministry of Science and Technology Key Research and Development Program, the Guangdong “Zhujiang Talent” team plan and the Shenzhen Science and Technology Plan.
Principle, structure, material and preparation process of electronic sensor paper
Application of electronic sensor paper on pulse wave measurement and origami piano
Application of Electron Sensing Paper in Pressure Distribution of Weight Measuring Kit and Handwritten Brush