Interesting idea, but I would say that it is orders of magnitude harder compared to having an integrated system. Vibration in such a compact space with a very sharp blade... I want this system be stable around me.
I would say, if this idea becomes popular, knife producers can create their own versions in the new models, or retrofit old knives at the shop.
Yeah, I'm already somewhat skeptical of the whole concept, having DIY'd a vibroblade out of an X-acto knife and a SonicCare toothbrush and finding it to be completely ineffective.[1]
I think trying to make an ultrasonic vibration add-on for regular knives would be even harder to make into a useful product than an integrated knife/transducer.
If the handle is rigidly fixed to the blade, there would be very little vibration. So it seems like the only way to make an add-on would be as a sleeve over the regular handle. That would make for a bulky handle, and it seems like it would need a counterbalancing weight at the back. So the result would be very unwieldy, like one of those electric turkey-carving knives that are basically kitchen hedge-trimmers.
I'm waiting to see what skilled chefs think of this knife. The idea of an ultrasonic vibroblade has always seemed like a neat one to me, and I'd be happy to hear that someone managed to make one that was genuinely useful.
Ultrasonic cutting board. "Are you tired of spending $1800 on a whole set of ultrasonic knives only to have them break every time your Brother in law throws them in a bowl of soapy water after a dinner party? Well know you don't have to. Image buying 6 cheap knives at a garage sale and turning them into chefs quality knives instantly, without even touching a sharpener!"
I would say, if this idea becomes popular, knife producers can create their own versions in the new models, or retrofit old knives at the shop.