An unmanned aerial vehicle (UAV), also known as a drone is an aircraft without a human pilot aboard.
Flying Microchips The Size Of A Sand Grain Could Be Used For Population Surveillance
NEW YORK - It's neither a bird nor a plane, but a winged microchip as small as a grain of sand that can be carried by the wind as it monitors such things as pollution levels or the spread of airborne diseases. The tiny microfliers, whose development by engineers at Northwestern University was detailed in



