Hi everyone !
In shops, one remaining Covid contamination path is money. An answer is to allege that money doesn't host the virus, I read that. Or we can try to tackle the problem.
UV light is known to destroy virusses, including Sars-Cov2. UV LED are available for near-ultraviolet Hg wavelengths, compact, reliable, efficient. This could irradiate the money between the cashier's and the customer's hands, in both directions.
The rest is mechanical design, still imprecise. The apparatus must stop the UV from exiting but irradiate both sides of banknotes and coins.
Both users could introduce the money at the top, say between a pair motorised soft rolls, and grasp it at the bottom, after an other pair of rolls. UV between the pairs of rolls would be blocked by the rolls. Nice for banknotes, but the coins would fall at once. It also needs a soft material that survives UV. This shape has the smallest footprint.
Or a platter would tun slowly. The customer has a sector to introduce and extract money, the cashier has an other sector, and the two sectors in between irradiate the money under a cover. Silica and variants make the platter transparent to UV.
Maybe banknotes and coins should have different paths. Possibly the soft rolls for banknotes and the platter for coins.
The apparatus must be easy to open, and opening must halt the UV emission. Fluorescent surroundings would reveal any UV leak.
Marc Schaefer, aka Enthalpy