Mosquito inspires painless needle concept

A team of Japanese microengineers has used the "stinger" of a mosquito as inspiration for a new type of syringe they say delivers painless injections, New Scientist reported.

Researchers at Kansai University in Osaka concluded that the stab of a mosquito's proboscis goes unnoticed by the host because it is covered with tiny serrations, limiting points of contact, according to the article. Consequently, nerves surrounding it go largely unstimulated.

The Kansai researches sought to mimic the proboscis' serration by fabricating a needle that copies the mosquito's mobile mouth parts. The needle is etched from silicon and has three parts that are driven by tiny motors based on lead zirconium titanate (PZT), which is a piezoelectric crystal that expands slightly when an alternating voltage is applied. The crystal vibrations are used as a simple motor that controls the entry of the needle into the skin in the same way a mosquito does, according to the article.