## 5 Future Trends and Perspectives
### UK Highlights  
RFID-based sensing and monitoring combined with printed electronic devices is leading the way over traditional sensors to have great potential for ground-breaking sensing and monitoring for infrastructures in extreme environments [201], and intelligent society including intelligent packaging [193] and wearable'smart' electronic devices for e-healthcare of ageing people at senior centre, hospital, or home [181]. The passive antenna sensors, in fact, is a new technique and have great potentials to be developed into permanent embedded sensors for ageing infrastructure and life extension: e.g., railway track [202], power plant [203], aircraft [204], oil & gas structures [205] and pipelines [206], where reliable and accurate defect assessment and continuous monitoring is thereby required to provide significant safety and economic benefits. More applications can be found in [207]. This needs interdisciplinary efforts, for example, material science: function material and properties, electronic engineering: electronics and circuit, microwave, information science: networking and convex optimization, and processes: machinery and fabrication. The related researches across the UK for these types of sensor are listed into several categories shown in Table 4.  
The current focus in additive antenna fabrication has been mainly to use metallic components as the conductive element. This brings some limitations, including the antenna quickly becoming corroded and oxidized and especially the high material costs. One of the most potential solutions lies on utilizing novel carbon-based nanomaterials, such as graphene, in RFID-based wireless components [124]. In addition to good printability, graphene inks offer great eco-friendly aspects and low material costs. Also, as graphene properties change accordingly with humidity and mechanical stress, by using graphene in RFID antennas, the changes in properties can be exploited into changes in wirelessly measurable parameters [183], providing a huge potential for wearable sensor applications. Above these, many new opportunities are emerging in the UK. For example, carbon-fiber reinforced plastics (CFRP) composites have been widely used in aerospace, shipping, and automotive structural applications, thanks to their superior stiffness and strength characteristics, fatigue and corrosion resistance. However, because of continuous use and exposure to events, the performance of composite structures can be easily affected in terms of local defects like fiber breakage, resin rich zones, delamination, and impact [208]. \begin{table}
\begin{tabular}{c c} \hline \hline
**Areas and Focus** & **Universities** \\ \hline Materials and graphene & University of Cambridge [209] \\  & University of Manchester [210] \\ \hline Wireless power transmission & Imperial College London [211; 212; 213] \\ \hline Antennas & Queen Mary University London [214; 215] \\ \hline Channel and communication & Queen Mary University London [216; 217] \\ \hline Security and privacy & University of Bristol [218] \\ \hline Sensors and systems & Newcastle University [49; 50; 51] \\ \hline Manufacturing & Loughborough University [219] \\  & University of Kent [220] \\ \hline Smart objects applications & Auto-ID Labs at University of Cambridge [221] \\ \hline WBAN for e-health monitoring applications & Queen Mary University London [222; 223; 224] \\ \hline \hline \end{tabular}
\end{table} 
Table 4: Related researches for the Universities in the UK. In order to cope with such a vision, the unique properties of defects on metal and CFRP should be detailed in order to make the sensor reliable. For example, the electrical conductivity of the CFRP is anisotropic and much lower than the metal counterpart, which is a major concern using EM method; while reduction of the permeability is another concern for corrosion. Furthermore, downstream of overall collaboration, based on the judge to integrated innovation to market demand is not easy for universities alone, and organizations such as RCNDE and TWI can find their benefits.