Wearable electronics is a hot topic these days. Although these fancy talons are only for show, they could lead to more in the future.
[Shelby] and [Colleen AF] showed people how to include a laser cutter in your nail care at a recent event at NYC Resistor. The technique used here starts off with a base coat of the background color before heading to the laser cutter. Now don’t worry, you don’t need to risk any of your digits. A type of reverse silk screen is made with the laser by deeply etching the artwork into a piece of flat acrylic sheet. Those voids are then filled with the secondary color for the circuit traces and the excess is removed with a squeegee. A sponge is then used to transfer the paint from the recesses in the acrylic to the nails.
Granted, PCB finger nails might not be your cup of tea, but it does make us wonder: What if conductive ink was used? Would it be possible to build a circuit on your own fingernail? Obviously you would want to use a sticky, conductive glue rather than solder. (Please don’t try to reflow solder your fingers at home.) What kind of power supply would fit? What could you build? We also see other possible applications of the process like labeling non-flat surfaces. Let us know what you think in the comments below.
UPDATE: [David Flint] points out in the comments that this is a type of offset gravure printing.
I have tried to solder my fingernails several times, actually. Not on purpose
No one please try and put your fingers in a laser cutter. Lasers give some of the deepest nastiest burns.
And the smell. you never ever forget that smell…
At least it cauterizes as it cuts, I hope?
From experience yes, yes it does.
As a bonus you get to see how wide your laser beam is. (You tend to do this only once).
A fingernail which is long enough to stick out past the fingertip can take the heat of molten solder for a minute or so. I’ve held leads down with a nail several times. It doesn’t stick very well though. you would need some copper foil tape or something to make that work. Hmm… this is starting to sound tempting. If I were a girl I think I would so be building an astable multivibrator (wee blinky) on my thumbnail tonight.
hint.. I want somebody to do this and submit it with pictures..
Forget the nails, I want to know more about this Unibus card…
https://trmm.net/Unibus
That’s… that’s beautiful. If only I still had that 11/34.
that was my exact thought also
That’s cool! It’s a shame my nails are so crap, otherwise I would totally try this. Could do so many different little icons and stuff.
For instance, on your middle fingernail you could have a little drawing of a hand showing its middle finger, and a “thumbs up!) on a thumbnail
LOL!
Good idea, my missus will be having a go at this now.
As a printer i would just like point out that this method of pigment transfer is known as offset gravure printing, to say “type of reverse screen printing” is misleading as screen printing uses a mesh screen and uses direct pigment transfer. Sorry for being podantic.
Thanks for that insight. I’ve updated the post with a link to rotogravure info.
It’s also the standard method of laying complex patterns on nails, simply with the laser etching happening on site.
More specifically it is Pad Printing http://en.wikipedia.org/wiki/Pad_printing It is distinguished by the use of the rubber pad intermediary to transfer the ink to compound curved surfaces.
Lithography/printing techniques are an incredibly important technological thread that runs from seals and stamps in 5000BC to the PCBs and SoCs in the latest smartphone. Its worth helping people be more precise in the language they use to describe it.
Also, the ink isn’t transferred with a sponge, it is transferred with a rubber pad.
Oh, and, FWIW, this popped up while searching on The Google:
Gravure offset printing of polymer inks for conductors http://www.sciencedirect.com/science/article/pii/S0300944003002194
A curved PCB would fit around AA batteries nicely. The trick is getting the parts onto the board. You are limited to extrmely small SMT, until someone makes curved semiconductor chips.
“Yes we have a 256 ball BGA, in 0.5mm spacing. But we don’t stock AAA curvature”
It may not need to be curved either, we are talking about crazy fashion ideas. So why not have mini flat circuit boards?
These situations are where you buy the bare die and skip the packaging. Just you, a tiny welder, and a little blob of epoxy. Make sure you identify pin 1.
This is so doable, here it is:
– get nail bed dimensions
– Use thin film circuits designed for nail (mini caps, LEDs, contact points to charge)
– adhear with removable nail glue
You could do different circuits that work with each other when you tap the side of the nails to each other, or have a battery glued on one that charges the others on contact. … I wonder if you could get a piezo buzzer on your fingernails!
Alternatively any medium would work as long as you could shape it!
Example:
use fake finger nails, apply copper cladding/foil and laser cut it, solder with cold heat iron or conductive glue.
Use PCBs that have had a curve ground into them
…. Wow after writing this out, I now want to try it. And I am a guy!
Let the discussion rampage commence.
That could be the best blood glucose monitor ever. Should be possible to pick up some small bits of electricity from under the nail if you are careful or just add a very small pedometer type generator.
Labeling non flat surfaces? you mean tampography (aka pad printing)? That’s been around since the 60s at least.
Those look great. Most of my nails are solder burned but I’d love to have this for the ones that don’t!
I would like to have an LED blinkenlight on my middle fingernail so that when I’m giving the proper salute, it will blink at about .5 to .75Hz
Embedding an auto blinking 0805 led in clear nail varnish should be trivial two pieces of 30 gauge wire down to a wrist band (maybe anchored mid way by a ring or something) with a momentary switch and a button cell or 041515 lipo would be easy enough to wire. I say go for it!
There are plenty of places that will embed tiny rhinestones in a nail (or extension). So this will just be adding some SMT to their repertoire.
If you want to build circuits on nails use fake nails, hey if it’s good enough for Laquisha it’s good enough for you.
Envision this in combination with a fingerprint scanner. Place the scanner at the bottom of a finger sized tunnel. Place the necessary number of spring contacts at the top. Insert your finger, scanner reads your print as 1st level confirmation, then reads the temporary pcb on your nail (by way of the contacts touching the proper points) as a 2nd level confirmation, action initiator, etc… Do this with multiple fingers, so that scanning a given finger with its particular pcb could trigger different actions (ie, scanning with this finger and pcb combo authorizes access, scanning with this other finger and pcb combo triggers a silent alarm, etc…).
Fanciful? Sure. More likely to show up in Hollywood than real life (come on, make this happen in Mission Impossible 8 or 9 or whatever we’re up to now)? Sure. But why the heck not? Protagonist knows which finger to scan, antagonist doesn’t, protagonist triggers the emergency beacon just in time, etc….
So many possibilities…
Now – make this a working circuit and put blinky led’s on it…. that would be cool !