Other short-range wireless chemical and biological sensors that are not based on the RFID protocol have also been described in the literature, and this growing body of work demonstrates the awareness of the advantages of non-contact biosensing. Different short-range contactless technologies have included, for example, surface acoustic wave (SAW) sensors [16–19], magnetoelastic sensors [20–23], tuned inductor-capacitor (LC) sensors [24,25],and fuel cell based biosensors [26,27]. Such devices are generally low cost, and do not require batteries or in some cases even active electronic circuitry in order to function, which makes their deployment extremely attractive in certain chemical sensing applications. However, the majority of such non-contact sensing devices are not network compatible, and do not support anti-collision protocols the ability of multiple devices to be interrogated simul-taneously. Both these attributes require active electronics, and therefore, in order to support these functions, the additional overhead in electronic complexity and cost must be incurred.By comparison, RFID-based devices can be batteryless, otherwise known as passive, yet do contain active electronics and are thus network compatible, scalable, and the relevant international RFID standards support anti-collision protocols with out being either overly complex or expensive to implement