Microtubes offer painless injections
A research team from Tokai University in Japan has developed a method of fabricating metal tubes with an external diameter as small as 50µm and an internal diameter of 25µm - no larger than the proboscis of a mosquito - that can be made into painless syringe needles.
A research team from Tokai University in Japan has developed a method of fabricating metal tubes with an external diameter as small as 50µm and an internal diameter of 25µm - no larger than the proboscis of a mosquito - that can be made into painless syringe needles.
In the procedure, titanium is sputtered onto a copper wire, which is then melted and removed, leaving a hollow tube of titanium. This is the same sputtering method used in semiconductor manufacturing, except the metal molecules are sputtered on copper wire instead of a flat substrate.
By changing the shape of the wire the tube can be designed with a polygonal crosssection. The university group plans to manufacture the microscopic tubes in different shapes to determine which shape makes the superior painless syringe needle.
Needles are currently produced by sharpening metal tubes, and the smallest needles are around 200µm in outer diameter. Furthermore, the needles tend to be made from chrome and nickel materials harmful to the environment.