If you have a project in mind that requires some sort of gesture input or precise movements, it might become a nettlesome problem to tackle. Fear this obstacle no longer: a team from the Wyss Institute for Biologically Inspired Engineering at Harvard have designed a novel way to make wearable sensors that can stretch and contort with the body’s natural movements.
The way they work is ingenious. Layers of silicone are sandwiched between two lengths of silver-plated conductive fabric forming — by some approximation — a capacitance sensor. While the total surface area doesn’t change when the sensor is stretched — how capacitance sensors normally work — it does bring the two layers of fabric closer together, changing the capacitance of the band in a proportional and measurable way, with the silicone pulling the sensor back into its original shape as tension relaxes. Wires can be attached to each end of the band with adhesive and a square of thermal film, making an ideal sensor to detect the subtlest of muscle movements.
Continue reading “A Flexible Sensor That Moves With You”
[Jesse Burstyn] and some colleagues at Queen’s University and Carleton University (both in Canada) are delivering a paper at the INTERACT 2015 about PrintPut, their system for printing sensors directly into 3D printed objects. Using a printer with dual extrusion and conductive ABS filament, they have successfully formed capacitive touch sensors, digital resistive sensors, and analog resistive sensors.
In practice, this means they can print buttons, sliders, and even touch pads directly into objects. They also have a design for several pressure sensors and a flex sensor. The system includes scripts for the Rhinoceros 3D CAD package. Designers can create a model in any CAD package they want (including Rhinoceros) and then use these scripts to define the interactive areas.
Continue reading “Buttons, Sliders, and Touchpads All 3D Printed with PrintPut”
[Chris] seems to have commandeered a decent portion of the wife’s sewing room for his electronic adventures. As it is still her claim, she made it clear that his area needed some organization and a new desk. Dissatisfied with the look and feel of the replacement IKEA desk-like substance they acquired, he took it upon himself to ratchet up both the style and value by adding a copper laminate.
His decision is not purely based in aesthetic. If you’re following along, this means that his new electronics work surface is conductive. And yeah, it’s connected to ground at the wall. Although he doesn’t care for the stank of of anti-static mats or their susceptibility to fading and cracking, he does intend to use a tiny patch of it to keep his silicon happy.
[Chris] used a 20-gauge copper sheet that he cut and scored down to fit his Swedish sandwich wood base with enough margin for overhang. After scratching up one side of the copper sheet and one of the receiving base, he squidged down some adhesive nasty enough to require the rubber glove protocol and clamped it all together for several hours. Stay put the copper did, but stay flat it did not. After hammering down the overhang, [Chris] hand-burnished the copper in small swirls with a Scotch Brite pad to visually break up the slightly wavy surface. Instructional and hilarious play-by-play after the break.
Continue reading “This One May Come as a Shock to Some”
We really like this take on a conductive wire maze game. It’s the result of a 48-hour hackathon in Belgium which required that all projects stemming from the event use an Arduino. We think [Jan] and [Kristof] made perfect use of the prototyping device in the time allotted. The event organizers thought so too because this took top prize.
As you can see, the gaming area is two-sided, and consists of some copper wire bent into a maze. There’s a wand made out of a PVC pipe with a loop of braided cable running through it. The loop surrounds the copper track and each player needs to get from the beginning to the end, touching checkpoints along the way without coming in contact with the track.
Pretty standard, right? Well there’s a twist. At each checkpoint the Arduino signals a servo motor in the wand to make the loop smaller. Add to that a penalty/reward system: if you touch the track, your loop gets smaller and your opponent’s loop grows larger. Don’t miss the head-to-head action after the break.
This reminds us of that wire-based cave racer from a few years back. Continue reading “Wire loop game penalizes for touches by shrinking your wand”
If you’re forever alone we’d guess you’ve long since stopped crying about it. But if you’re still prone to shed a tear on a dateless Valentine’s day this project’s for you. [Mikeasaurus] spruced up this pillow to play a tune when it senses your lonely soul. It’s got a moisture sensor which triggers an audio greeting card just when your weeping really starts to get soggy.
If you look closely at the top portion of the white fabric in the picture you can see there are rows of stitching. These hold a matrix of conductive wire mesh fabric on the inside of the pillow case. There are two buses made up of alternating rows (think of the tines of two forks pointed together) which make up the probes. When the gap is bridged by moisture a transistor circuit triggers the audio bits from a greeting card to play a song. Check out the demo after the break. We’re not satisfied that [Mikeasaurs’] couldn’t even bring himself to cry real tears for the clip, but maybe years of solder fumes have clogged up those tear ducts.
Continue reading “Tears from your lonely heart will activate a comforting tune”
Why spend time etching circuit boards and applying solder masks when all you really need is a rollerball pen and some paper? That’s what University of Illinois professors [Jennifer Lewis and Jennifer Bernhard] were asking when they set off to research the possibility of putting conductive ink into a standard rollerball pen.
The product of their research is a silver nanoparticle-based ink that remains liquid while inside a pen, but dries on contact once it is applied to a porous surface such as paper. Once dry, the ink can be used to conduct electricity just like a copper trace on a circuit board, making on the fly circuit building a breeze.
Previous ink-based circuit construction was typically done using inkjet printers or airbrushing, so removing the extra hardware from the process is a huge step forward. The team even has some news for those people that think the writable ink won’t hold up in the long run. The ink is surprisingly quite resilient to physical manipulation, and they found that it took folding the paper substrate several thousand times before their ink pathways started to fail.
While we know this is no substitute for a nicely etched board, it would be pretty cool to prototype a simple circuit just by drawing out the connections on a piece of paper – we can’t wait to see this come to market.
If you’re into embedded clothing this stroke sensor is for you. As demonstrated in the video after the break, stroking the threads in a particular direction will create a circuit that senses and, in this case, turns on an LED. The concept uses two conductive buses on the back of a piece of neoprene. Conductive and non-conductive threads are then added for a furry or bristly finish. When stroked perpendicular to the power buses the conductive threads come together and form a circuit.
For some reason this just seems a bit creepy to us but perhaps that’s only because we haven’t come up with the right application for the technology. We’re pretty sure that a sweatshirt with an LED marquee and a “hairy” back that you stroke to illuminate is the wrong application.
Continue reading “Stroke to unlock”