USA: A wind-up vaccine refrigerator has been named the US Winner of the James Dyson Award.
The innovative product was designed by Rogers Feng, a student of Northwestern University in Chicago, who recognised the challenge of storing drugs and vaccines in developing countries where power is unavailable or, at best, unreliable.

Most need to be kept at a constant temperature between 2 and 8 deg C and under current methods there can be a high level of waste. Even if the regional hospital has refrigeration equipment, the vaccines still need to be distributed to individual villages. Vaccine distribution workers typically use ice boxes and are faced with two problems as a result. First, they must race against the melting of the ice. Second, accidentally packing too high an ice-to-vaccine ratio would freeze the vaccines and destroy them.

These challenges make for some pretty tough odds. In fact, the World Health Organization reports that vaccine wastage rates may be as high as 50% in some cases. Both lives and money are being lost.

Rogers Feng's vaccine refrigerator is operated by using a hand crank for about 5 minutes to power the device. It can then run for about 15 minutes before needing to crank it again. The crank powers a small DC generator that charges a 9V rechargeable Li-ion battery. In turn, the battery powers Peltier units which carry out thermoelectric cooling.

The design is said to have three main advantages. First, the circuitry prevents sudden drops in ambient temperature from causing freezing, which would destroy vaccines, with an active feedback loop. This is a safety feature that some developing world-oriented refrigerators lack. Secondly, there are no refrigerant fluids that could potentially leak. Lastly, the design is inexpensive; with an estimated unit cost of $50 (a solar-based equivalent would cost several hundred dollars).

The James Dyson Award is an international student design award running in 18 countries. It's run by the James Dyson Foundation, James Dyson's charitable trust, as part of its mission to encourage the next generation of design engineers to be creative, challenge and invent. The Award has received nearly 550 entries from 18 countries. As the US winner Rogers Feng will receive $1,400 and move on to the international final, which will be held in November.