Design and Development of Efficient and Conformal Printed Antennas for Wireless Sensing and Wearable Applications

Future wireless technologies would require flexibility from electronics that will enable the electronic components to adapt according to the everyday use environment. Flexible electronics has been used in many wireless sensing and wearable applications. One of the fastest growing wireless technologies of this decade is Radio Frequency Identification (RFID) which is an automatic identification technology that uses electromagnetic interaction to identify, sense and track people or objects with transponders known as tags. RFID is rapidly replacing the bar code technology in supply chain applications and huge amount of tags are needed to be produced in order to meet the needs of this application. The production method and material selection are few of the key parameters which are under study for the cost-effective and efficient fabrication of RFID tags and wearable antennas. The latest manufacturing technologies such as inkjet, thermal and three dimensional (3D) printing have shown good potential in improving the fabrication process, however they need to be optimized and explored further to get the best possible results.This thesis reports the use of novel manufacturing methods for the development of passive Ultra High Frequency (UHF) RFID tags and wearable antennas on versatile substrates. Commercially available as well as 3D printed flexible substrates along with different conductive inks/pastes are used for the improvement in the fabrication process. The first part of the research compares inkjet and thermal printing for the RFID fabrication in detail and suggests suitable optimizing parameters for the materials under study. The second part of the research focuses on 3D printing of the substrates and then utilizing brush painting, 3D dispensing and embroidery process to improve the overall fabrication. In addition, the fabricated antennas are tested for humidity, bending and stretching for specific applications.The results indicate that the approach and methodologies used have great potential in improving the fabrication of RFID tags and antennas. The fabricated tags show excellent results and achieve the required performance for modern RFID applications such as supply chain, wearable biomedical sensing and environment monitoring. This detailed study will be very helpful to find out appropriate materials for fabricating wireless components with the best possible results, i.e. easy to fabricate, reliable and better wireless performance, for future applications such as Internet of Things (IoT) and smart RFID packaging