Review and Application of Electronic skin

Summary

Electronic devices that mimic the properties of skin have potential important applications in advanced robotics, prosthetics, and health monitoring technologies. This paper, based on the development of electronic skin in recent years, and the defects of current wearable devices, presents the electronic skin structure and future applications applied to the mobile health field. The electronic skin used in mobile health mainly consists of flexible substrate, multi-sensor, microcontroller, flexible power supply and wireless communication. Sensors, microcontrollers, power supply and wireless communication are all integrated on flexible substrates, communicating with intelligent terminals, and transmitting signals to intelligent devices. By means of cloud computing and analysis, real-time monitoring of human physiological information can be realized.

Catalogs

Introduction

Ⅰ. Foreword

Human skin, showing notable features, is a physical barrier for us to interact with the surrounding environment, which enables us to perceive different shapes and textures, temperature changes, and different levels of contact pressure.It is an integrated, scalable sensor network that delivers tactile and thermal signals to the brain, enabling us to operate safely and efficiently in the surroundings. Inspired by these characteristics of the human skin, researchers are working to create a flexible, scalable, highly sensitive electronic device. Therefore, the development of electronic skin has become a research hotspot, especially in the fields of intelligent robot and e-health.

Basic functions of electronic skin:

1. 1. From obtaining physical stimuli to distributed sensor arrays;

2. 2. Preprocessing sensor signal;

3. 3. Wireless transmission of signals to higher-level systems (e.g. smartphones)

While some of the current wearables also offer these features, but can not reach the wafer-thinness, feather-lightness, high strain sensitivity as ultra-thin electronic skins. More importantly, the electronic skin is equipped with highly sensitive conductive nanomaterials, which can accurately induce a slight tremor of electrical change of a muscle group. At the same time, electronic skin is scalable (for example, it supports joint motion), and can even form integrated chemical sensors and biosensors. The adhesion of electronic skin is better, the preparation process is simpler and the cost is lower, which makes us would like to say the future market will belong to electronic skin. In this article, We'll have a discussion about electronic skin in three aspects: the development, the architecture system in e-health field and the applications of it, and in the end the future and prospect of e-skin have also been discussed.

A micro-electronic health monitor so thin, light and portable that it can attach right to the surface of skin and go wherever a person goes. This innovation has the potential to revolutionize the field of healthcare technology.

Ⅱ. The development of electronic skin technology could be divided into two stages:

1. 1）From 1970s to 1990s, the concept of e-skin appeared for the first time and got a preliminary development.

2. 2）Since 2000s, more researchers have been involved and have made a significant progress in recent years.

In 1974, Clippinger demonstrated the feedback of a discrete sensor for a prosthetic hand. In 1985, General Electric first built a robotic arm sensitive skin which enabled to interact with the environment, placed on a flexible, curved sheet using discrete infrared sensors. In the 1990s, more and more teams began to create large-area, ultra-thin, multi-sensor flexible sheets. Jiang et al. first proposed a bent sensor sheet which obtained by etching thin silicon wafers and then integrating them on flexible polyimide film. In 2000, the organic transistor electronic nose was developed. Later, more achievements were made, such as scalable inverters, flexible active matrix technology, high resolution optical sensors, microstructured pressure sensors and so on. In 2003, the research team at the University of Tokyo in Japan made thin films by using low molecular organic compounds and realized the pressure of electronic skin through the pressure sensors on its surface. In 2010, the University of California, Berkeley, developed a technology to attach nanowire transistors to a sticky substrate, the resulting e-skin therefor could apperceive less than 50 grams of fine pressure and has been subjected to bending 2000 times. A woman scientist of Stanford University Bao Zhenan and her team have developed a highly sensitive flexible plastic film material that mimics human skin and senses subtle pressure. At the same time, the team developed the world's newest stretch solar cells, allowing electronic skin to self-generate electricity. In 2011, a researcher named John A.Rogers introduced an electronic patch for monitoring patient vital signs which described as "electronic skin." This device embedded the sensors in a film and placed the film on a flexible polyester substrate, like a kind of tattoo on the body. physiological indexes of human health In 2014, electronic skin, developed by a researcher from the Chinese Academy of Sciences, was pasted on the human skin by static electricity, enabling real-time monitoring of physiological indexes of human health such as pulse, heartbeat, body temperature, muscle group vibration and so on, to promptly make a respond with feedback on changes of human health data.

Detail

Ⅲ. Electronic skin system architecture

Compared with the current intelligent wearable devices, electronic skin has the characteristics of high sensitivity, ultra-thin, bendability and comfort in guardianship and monitoring the important physiological information of human body. E-skin system is a new type of flexible and extensible sensing system. By making sensors and circuits built on flexible substrates, e-skin systems can obtain unique ductility and more sensible to the various physical, chemical and biological signals. In the field of health care, the emergence of electronic skin will change the imprecise measurement of wearable devices, reduce the number of heavy monitoring equipment in the ward, and enable medical staff obtain the patient's physiological parameters in real time.