Microchip marvel
A radar system on a microchip, costing less than $10.5 has been developed by American scientists. It is so sensitive that it can monitor the breathing of a baby to cut down cotdeaths, pinpoint human heartbeats in collapsed buildings, detect burglars, find landmines, replace the doctor's stethoscope or simply help park the car. Unlike the conventional radar, which sends out continuous waves, this one, called Micropower Impulse Radar, uses short elecromagnetic pulses. Powered by two 1.5 volt batteries, it detects echoes of its signals from objects from between 15 cm to 100 metres, and can be enhanced to reach up to 500 m.