Flexible Antennas for Wearable Technologies

Introduction

The terms “wearable technology”, “wearable devices”, and “wearables” all refer to electronic technologies or computers that are incorporated into items of clothing and accessories which can comfortably be worn on the body. For example, one function of an activity bracelet takes raw data from a sensor, processes it and generates a report on the number of steps taken over a given period. Sensors track motion with enough intelligence to distinguish between steps and other movements.

Sensors/ Antennas are an important part of wearable electronics, and continue to become smaller and more sophisticated. While there are many types of sensors that can be used, the most common is an inertial measurement unit (Accelerometer). An accelerometer can track a specific movement, its direction, and its intensity or speed. One simple example of an accelerometer is when a mobile phone or tablet (the input) is rotated and the device processes the movement and rotates the screen accordingly (the output). Other common sensors including pressure, temperature, position and humidity, support applications such as GPS. Consistently, wearable and flexible devices would often require the integration of antennas operating in specific frequency bands to provide wireless connectivity which is greatly demanded by modern information-oriented consumers. The aim of this study is to provide an overview of the current status and future perspectives in research and development of wearable technologies and sensors, to afford a comprehensive guide to various technologies and methods applied in the realization of flexible and wearable technologies along with state of the art antenna designs and implementations. Moreover, this document serves as an extensive reference in wearable topics. For these goals, it is necessary to define the field of wearable systems.