Microbots that can hitch-hike
Scientists at Harvard University, USA, have developed flying microrobots that can use static electricity to perch on bats, birds or butterflies to conserve energy in long-duration flights.
The team at Harvard has used electrostatic adhesion, which is the same basic property that causes a static-charged sock to cling to pants, or a balloon to stick to a wall.
Moritz Graule, a researcher on the project, has said, “In the case of balloons, charges dissipate over time and the balloon eventually falls down. In our system, a small amount of energy is constantly supplied to maintain the attraction.” 
RoboBee uses an electrode patch and a foam mount that absorbs shock. It takes off and flies normally. When the electrode patch is supplied with a charge, it can stick to almost any surface, from glass to wood to a leaf. To detach, the power supply is simply switched off.
The entire mechanism weighs 13.4mg, bringing the total weight of the robot to about 100mg—similar to that of a real bee.
