Less Painful, Mosquito-Style Needles

Whatever the red, itchy aftermath, a mosquito’s initial injection is often painless. The bug’s serrated proboscis touches the skin’s nerves at fewer points than it would if smooth.

A painless “microneedle” that mimics the way a female mosquito sucks blood has been built by engineers in India and Japan.  The needle could be used to draw blood, inject drugs, and as a glucose-level monitor for diabetics.
A female mosquito sucks blood by flexing and relaxing certain muscles in its proboscis. This creates suction (or negative pressure) that draws blood into its mouthparts.
The new biocompatible microneedle, designed by Suman Chakraborty of the Indian Institute of Technology in Kharagpur and Kazuyoshi Tsuchiya of Tokai University in Kanagawa is based on the same principle.
In this case, the sucking action is provided by a microelectromechanical pump, which works using a piezoelectric actuator attached to the needle.

Contrary to popular belief, a mosquito bite does not hurt. It is the anticoagulant saliva that the creature injects to stop your blood clotting that causes inflammation and pain.


ref : https://www.newscientist.com/article/dn14348-painless-needle-mimics-a-mosquitos-bite/