Coffee Time Challenge Solution: Smart Cat Flap
The solution to this month's challenge is the brainchild of Cambridge scientist, Dr Nick Hill. He has devised a system powered by four small batteries that identifies the owned cat by remotely reading its implanted chip.
This in turn unlatches the cat flap.
Andy Bank, General Manager of Cambridge start-up company SureFlap, said that if Dr Hill had used conventional embedded chip reading technology, it would have had to be a mains powered device. Without going into details, he told us that, "The breakthrough is in the circuit design, in that it automatically tunes and removes any upper limit antenna efficiency that may be used. This allows the use of high efficiency antennae that would otherwise require very fine setup."
An additional benefit of this automatic tuning is that it can compensate for the effects of detuning, which is a major problem with RFID systems. This is where the resonant frequency of a reader or tag changes through variations in components and/or the presence of metal and/or water in the vicinity, as in this case where it forms a large part of the cat.
Dr Hill says: "Our technology allows the system to compensate for this and can be applied both in a reader and also for the very first time in a passive RFID tag. This is set to have a major impact on RFID as a whole."
The SureFlap is sold by Yorkshire based Animalcare, the UK distributor of the Identichip microchip. The device sells for £79.99 and runs off four standard AA batteries. An optical sensor detects the cat, and the device can be taught to permanently recognise up to 32 chipped cats and keep out the others.
Dr Hill's company, Cambridge Resonant Technologies has patented the base technology called Ontune and is interested in licensing it for other uses.
