HairIO: An Interactive Extension of the Self

Most of what we see on the wearable tech front is built around traditional textiles, like adding turn signals to a jacket for safer bike riding, or wiring up a scarf with RGB LEDs and a color sensor to make it match any outfit. Although we’ve seen the odd light-up hair accessory here and there, we’ve never seen anything quite like these Bluetooth-enabled, shape-shifting, touch-sensing hair extensions created by UC Berkeley students [Sarah], [Molly], and [Christine].

HairIO is based on the idea that hair is an important part of self-expression, and that it can be a natural platform for sandboxing wearable interactivity. Each hair extension is braided up with nitinol wire, which holds one shape at room temperature and changes to a different shape when heated. The idea is that you could walk around with a straight braid that curls up when you get a text, or lifts up to guide the way when a friend sends directions. You could even use the braid to wrap up your hair in a bun for work, and then literally let it down at 5:00 by sending a signal to straighten out the braid. There’s a slick video after the break that demonstrates the possibilities.

HairIO is controlled with an Arduino Nano and a custom PCB that combines the Nano, a Bluetooth module, and BJTs that drive the braid. Each braid circuit also has a thermistor to keep the heat under control. The team also adapted the swept-frequency capacitive sensing of Disney’s Touché project to make HairIO extensions respond to complex touches. Our favorite part has to be that they chalked some of the artificial tresses with thermochromic pigment powder so they change color with heat. Makes us wish we still had our Hypercolor t-shirt.

Nitinol wire is nifty stuff. You can use it to retract the landing gear on an RC plane, or make a marker dance to Duke Nukem.

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DIY Curved Display Makes Use of Cool Thermochromic Properties

flexible screen

[Marin Davide] was on a mission. A mission to build his own curved display screen, using an Arduino, nichrome wire, and thermochromic liquid crystal ink.

The prototype he’s designed uses a sheet of plastic coated in thermochromic ink, curved on an MDF frame. This particular thermochromic ink turns bright blue when heated to around 27°C.

To display digits, he’s created tiny segments of the 7-segment display by wrapping the nichrome wire around pieces of cardboard, which then have been glued to the back of the display. Each of these is controlled separately from his Arduino Mega. He muses that you could also make a rudimentary dot matrix display with this — it would be interesting to see what kind of resolution you could obtain!

To see more photos check out the original DesignNews post linked above. We’re not sure why the bulk of the details are only available in this PDF. If we’re just missing a direct link to the original project page let us know in the comments and we’ll update the post.

Interested in more thermochromic black magic? How about these awesome temperature sensitive photos? Or what about a digital clock face, illuminated by heating resistors?

Thermochromic Imaging

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[clarii_d] is currently finishing up her thesis project on thermochromic pigment to silkscreen receipts. The idea behind it is that when a receipt is touched, part of it fades revealing a hidden message.

As you can guess, thermochromic paint is a type of substance that changes color when introduced to heat — or in this case, fades altogether. Remember when mood rings were all the rage? Same thing.

In her project she is using silkscreening to transfer text onto the back of receipt paper using regular ink. Once dried, she silkscreens an image over top of the message, this time using a thermochromic pigment. The result is a slightly obscured image, but after holding it for a few seconds, it disappears and only the text remains.

Color-changing anything is a bit gimmicky, but we think [clarii_d’s] project is a pretty cool and unique application of it. A few years ago we shared another interesting project utilizing thermochromism; a color-changing clock face that utilized the heat given off by resistors!