What we would need is a UVA light source (wavelength range about 350 to 420 nm, other radiation is allowed too), based on LED, Fluorescent or other technology. The size should be rather small (length Please, note that long operating lifetime is also one point in our wish list as this device will have to operate 24/7 for long periods of time. 50 000 - 100 000 hours would be fine.