The Worldaware Award 2000 for Innovation
The Winner: Roke Manor Research Ltd.
Every 20 minutes someone somewhere in the world is killed or maimed by a landmine. A hundred million of them are believed to lurk in the soil of Angola, Cambodia, Somalia and other battlegrounds, and it costs up to a thousand dollars to get rid of a single mine. Only 100,000 are cleared in a year. One reason for the high cost is that equipment to detect mines needs batteries, maintenance and often trained operators. The more sophisticated kit requires specialist teams. Many mines are in forests where solar power cannot be generated.
Two years ago Chris Richardson, a consultant at Roke Manor Research, Romsey, was asked to produce something to demonstrate Roke Manor's expertise in low-power devices. He produced a mine detector which is cheap to make, needs no batteries, requires little maintenance and can be used with little training. Roke Manor calls it SPLICE - self-powered locator and identifier for concealed equipment.
As the user sweeps the detector over the ground, it generates enough power from the sweeping action to do its job and give the user audible signals. It needs no batteries. The power generated by the sweep goes to a transformer and then a capacitor which delivers two milliwatts. "We wanted to devise a cheap, ruggedised machine that could be issued to everyone in a village," says Chris Richardson. "I am convinced that this simple device, if mass-produced, could halve the rate of mine casualties."
Conventional mine and metal detectors usually use a coil to create a magnetic field. A metal object disturbing the field will disturb the current in the coil. Chris Richardson adopted a different approach. In Roke Manor's device, two loops of aerial are printed on a circuit board. The outer loop transmits low-power radio signals. The inner loop, the receiver, is in a figure of eight. Normally, the receiver registers no signal because the two halves of the figure of eight cancel each other out. For the same reason, it gives no signal if the ground over which it is being swept is uniform in character, because the radio signals being reflected to the receiver are then similar. But if the ground under one half of the figure of eight differs from that under the other half, a signal is registered and it is amplified for the operator to hear. The signal also clearly marks the edges of the object located. Results from different radio frequencies can suggest what the object is made of, since different materials respond differently. The task of dealing with a mine remains; but at least it has been located. Tests by the Defence Evaluation and Research Agency found that SPLICE could locate mines five centimetres (two inches) below the surface. It could locate a stainless steel pin less than two centimetres long. Roke Manor is negotiating with two companies interested in manufacturing SPLICE.
Roke Manor is also working with a Canadian company, Hystar, which wants to use SPLICE with its remotely controlled helium balloons. The balloons would hover over suspect ground and lower SPLICE on a platform to survey it.
Roke Manor Research Ltd was set up in 1956 by the Plessey radio and telecommunications company. Siemens took over Plessey, and Roke Manor now serves Siemens's mobile phone, internet and telecommunications businesses. It is pursuing another use for the SPLICE technique: detecting small pieces of metal lodged in people's eyes. It can spot a fragment only a tenth of a cubic millimetre in size.