It’s CES week, and as usual, I wanted to have a look at the wackiest tech products put out this week and figure out the tech behind it. This year that pick is iPolish, the press-on nails that change colour with a phone and a small wand. Search online for the product demo videos, it’s pretty good.
If you strip away the fancy stuff, it’s a form of e-paper screen. They call it a screen with “Electrophoretic nanopolymers”. Electrophoretic just means charged pigment particles move in a fluid when you apply an electric field. The pigment you pull to the top is the colour you see. Once set, it is stable and needs no refreshing or power to retain the colour. I have previously written about the ePapers and how it works in detail if you want to read more about it.
I looked into the patents filed. It describes a stack that feels like a tiny curved display. There is a nail blank, transparent electrode, microcapsule pigment layer, and a patterned backplane electrode with traces. It comes with a unit called as wand which is controlled via BLE from your phone app. You choose a shade, but it’s stored as a colour file that is basically a voltage list. For the movement of particles (for colour change) you can’t just give a DC voltage, You typically need a balanced pulse sequence in the ±15 V to ±20 V range to avoid ghosting and charge trapping. The wand pushes that waveform through metal contacts on the back of the nail. Contacts are like a programming header to configure and then retain the colour.
Pricing seems to be around $99 and after that around $3.5nail for replacement. The website talks about the nail being active only for 30 days. I’m not fully sure if that’s a real electrochemistry or materials lifetime limit OR it could be purely be the company chasing the subscription revenue model, which I would say is a downer.
Anyways interesting tech. The core idea is solid. If they can manufacture a curved, addressable e-paper laminate this cheaply, the obvious next step is larger form factors. Colour changing dresses probably…
