Smart packaging: Acoustic sterilisation

I should have written this on the ides of March, but hey ho. I was discussing packaging this morning for an IoT event.

Imagine a bacterium sitting on a package on a supermarket shelf is called Julius Caesar. Now imagine Brutus coming along with a particularly sharp knife and stabbing him hundreds of times. That’s my idea, just scaled down a bit.

This started as a slight adaptation of an idea I developed for Dunlop a few years ago to make variable grip tires. (Still waiting for Dunlop to make those, so maybe some other tire company might pick up the idea).

The idea is very simple, to use tiny triangular structures embedded in the surface, and then pull the base of the triangle together, thereby pushing up the tip. My tire idea used electro-active polymers to do the pulling, and sharp carbon composites to do the grip bit, or in this antibacterial case, the sharp knife. Probably for packaging I’d use carbon nanotubes or similar as the sides with which to stab the bacteria, but engineers frequently come up with different nanostructure shapes so I’m pretty agnostic about material and shape. If it ruptures a bacterium, it will be good.

An easier to use alternative for widespread use in packaging would be to ditch the electro-active polymer and associated electronics, and instead to use a tuned acoustic wave to move the blades in and out of the surface. All that is needed to activate them is to put out that frequency of sound through a speaker system in the supermarket or factory. The sound needed would likely be ultrasonic, so it doesn’t irritate all the shoppers, and in any case, nano-structures will generally be associated with high frequencies.

So the packaging would include tiny structures that act as the dagger attached to a particular acoustic mass acting as Brutus, that would move when the appropriate resonant frequency is broadcast.

This technique doesn’t need any nasty chemicals, though it does need the nanostructures and sound and if they aren’t designed right, the nanostructures could be just as harmful. Anyway, that’s the basic idea.