London, July 18 : A team of Indian and Japanese scientists have created a painless "microneedle" that mimics the way a female mosquito sucks blood.
Suman Chakraborty of the Indian Institute of Technology in Kharagpur, and Kazuyoshi Tsuchiya of Tokai University in Kanagawa say that their new biocompatible microneedle may be used to draw blood, inject drugs, and as a glucose-level monitor for diabetics.
The researchers highlight the fact that a female mosquito sucks blood by flexing and relaxing certain muscles in its proboscis, which creates suction and draws blood into its mouthparts.
Saying their microneedle is based on the same principle, they have revealed that it has a microelectromechanical pump to create suction, which works using a piezoelectric actuator attached to the needle.
The research team has revealed that the needle has an inner diameter of around 25 microns and an external diameter of 60 microns, which is about the same size as a mosquito's mouthpart.
According to them, the needle's size and the fact that it works by suction makes it painless.
It is robust because it is made of stronger titanium and related alloys, which dramatically reduces the risk of it snapping during injections.
The needle is also strong enough to penetrate as far as three millimetres into skin and reach capillary blood vessels, and may be used to inject insulin or other drugs into the patient when required.
"The working principle of this device follows on from our discovery that in a well-designed microneedle, surface tension forces may overcome resistance from friction and draw up blood with unprecedented efficiency," New Scientist magazine quoted Chakraborty as saying.
The researchers hope to commercialise their needle, but there are still some challenges to overcome, such as scaling up the fabrication method and making it more user-friendly.
"This new blood extraction is interesting, but I question its ability to be fabricated and initialised en masse," said Geoffrey Thomas of the University of Calgary, Canada, who is working on a similar blood glucose sampling and analysis project.
A report describing the new needle has been published in the Journal of Applied Physics.