Tiny linear motor helps diabetics

. It was developed by the Cambridge Design Partnership to form an essential part of the Pelikan Sun automatic lancing device to pin-prick skin to produce a small drop of blood for diabetic blood sugar monitoring. Pelikan Technologies is based in Palo Alto, in California. According one of the three directors and founders of the company, Matt Schumann, “For the user, the process is painless.” A lancet is projected from a sealed and sterilised cassette of 50 lancets, and then the motor withdraws the lancet back into the cassette again. “In linear motor terms, there is nothing else like it on the market,” he says. While it may eventually be superseded by one of the 150 or so developments aimed at producing a reliable and accurate non-invasive method of monitoring blood glucose, there is still a need to test blood samples directly. The motor has a 5,000-to-1 dynamic range and as well as delivering speed and accuracy, will happily run at 2mm/s. It was developed in Matlab and Simulink from MathWorks UK. Cambridge Design Partnership co-director and co-founder Mike Beadman says: “We looked at voice coils and other possible alternatives but rejected them. While the motor is not the most power efficient solution, it delivers the dynamic range we needed in a very small package.” Now that the company has developed the motor, it is actively looking at other applications. “We could increase the efficiency for other applications and we can make it precise to 1 micron, although on the launch product it is precise to 50 microns,” says Beadman. “We are also working on sensor feedback.”