## 6 Future Opportunities  
Futurists and antenna designers have been discussing the idea of wearable technology for nearly two decades. Generally, the integration of wearable technology into main stream society has been slower than expected. This was due to a combination of the technology not being ready and insufficient market pull.  
Current technology is driven by the need for data and connectivity. There were one billion smart phones sold in 2013 [116]. This is evidence that people not only want technology, but they will spend money if it enhances their quality of life. Sensors that communicate voice, video, physiological environmental and location data will become increasingly ubiquitous. It is predicted that there will be 50 billion devices connected to the internet by 2020 [117].  
The feeling that wearable technology is on the cusp of going mainstream was exemplified by the level of interest at the Consumer Electronics Show in Las Vegas in 2013 where wearable technology was one of the main talking points [118]. There are now many devices on the market integrated into wrist bands that monitor the calories a person burns per day. The market for wearable technology is estimated to be worth more than $5 Billion by 2016 [119] and this market includes medical, fashion, sports, military and emergency services [32]. Other estimates have this value as high as $19B by 2018 [120]. 400 million smart watches are expected to be sold by 2020 [121]. Intelligent glasses with a small screen in front of the eye [122] are now available. Major industrial companies are moving into the wearable technology area [123].  
Currently, two thirds of hospital beds in the UK are occupied by people over 65. Furthermore, it is predicted that 10 million people alive in the UK today will live to the age of one hundred [124]. These numbers indicate that the current medical care of the ageing population is not financially sustainable without technological assistance. Telemedicine and remote monitoring can allow patients to be monitored in their own homes or with less medical supervision which will give more comfort to the patients. An example of this is electrocardiography (ECG) systems which monitor heart rate of patients by using antennas integrated into plasters [125]. There are also big opportunities for both recreational and professional athletes.  
The requirement for wireless connectivity means that every device may have at least one antenna. Currently the electronics and battery are rigid items and therefore a rigid antenna can also be included without inconvenience, especially at 2.4 GHz where PIFAs are small. Many observers believe that the next step will be for this technology to become truly wearable and be integrated directly into clothing where textile antennas will be required. Electronics is continuing to shrink in size and emerging technologies may allow the textiles themselves to harvest energy [126]. RFID tags in clothing are a current suitable candidate for fabric antennas as no battery is required and the RFID chip is very small so the use of flexible antennas will improve user comfort. Ongoing research into flexible batteries and flexible electronics will further drive the desirability for flexible antennas.  
Textile wearable antennas have the advantage that they can be integrated directly into clothing; are aesthetic and do not need to be handheld which allows the technology to exist without the user consciously being involved. By making antennas out of textiles, the size limitations become the torso size and not just the size of the device. This relaxation of the size constraints can increase the gain and bandwidth. This has particular relevance to lower frequencies where the wavelengths are larger.