Designing Flat Flexible PCBs

You can find flex PCBs in just about every single piece of consumer electronics. These traces of copper laminated in sheets of Kapton are everywhere, and designing these cables, let alone manufacturing them, is a dark art for the garage electronics wizard. Having these flat flex cables and PCBs manufactured still requires some Google-fu or a contact at a fab house, but at least now designing these cables is a solved problem.

[Oli] needed a way to connect two PCBs together over a moving part. Usually this means some sort of connector or cable, but he’s developed an even better solution – flexible PCB connections. To generate these copper traces sandwiched between a few layers of Kapton, [Oli] wrote a Python script to take a set of parameters, and produces an design for Eagle that includes all the relevant bits.

Of course, with a flexible PCB layout, the question of how to get these manufactured comes up. we’ve seen a few creative people make flexible PCBs with a 3D printer and there’s been more than one Hackaday Prize project using these flex PCBs. [Oli] says any manufacturer of flexible circuits should be able to reproduce everything generated from his script without much thinking at all. All we need now is for OSH Park to invent purple Kapton.

You can grab [Oli]’s script on his GitHub.

Organic Chemistry Circuits are Flexible and Work Wet

As circuits find their way into more and more real-world environments, the old standard circuitry isn’t always up to the task. It wasn’t that long ago that a computer needed special power, cooling, and a large room. Now those computers wouldn’t cut it for the top-of-the-line smartphone. However, most modern circuits don’t bend well and don’t like getting wet.

An international team of researchers is developing chemical-based circuitry that uses gold nanoparticles and electrically charged organic molecules to build circuit elements that behave like semiconductor diode junctions. It’s simple to make flexible circuits that don’t mind being wet using this chemical soup.

In an interview with IEEE Spectrum, the developers mentioned that other circuit elements similar to transistors and light sensors should be possible. The circuits aren’t perfect, however. The switching speed needs improvement. Also, while conventional circuits don’t like to get wet, these chemical circuits have difficulties if things get dry. Still, like all technology, things will probably improve over time.

This technology needs a good bit of engineering refinement before it is practical. If you need flexible photosensitive circuits in the near term, you might try here. Meanwhile, waterproof circuitry just needs the right kind of enclosure.

Photo Credit: UNIST/Nature Nanotechnology

Hackaday Prize Semifinalist: Bendy Solar Bluetooth Tags

Last January, [DrYerzina]’s sister couldn’t find her cat. The family searched the neighborhood for two hours until the cat came out from underneath a bed, proving once again cats own humans, not the other way around. A solution to this problem would come in the form of technology, specifically as [DrYerzinia]’s entry for the Hackaday Prize, a solar-powered Bluetooth tracking device. Yes, you can go on Amazon or eBay and buy a BLE tracker, but this version comes in a handy package: it’s built of a flexible circuit board to fit just about everywhere, including on the collar of a cat.

[DrYerzina]’s Bluetooth tracker is built around an Bluetooth LE module, with a few added passives, LEDs, and other parts glued and soldered onto a double sided, flexible PCB. To this, he’s added a flexible solar cell and a flexible LiPo battery. All of this is stuffed inside an enclosure 3D printed in flexible filament.

While the Hackaday Prize is filled with wearables, [DrYerzina]’s project is at the forefront of hombrew wearable technology. Nowhere else in the prize have we seen a dedication to making a device that bends. The best part is, he’s actually building a useful device; with just 15 minutes of sunlight a day (a condition very likely for a sleeping cat), this Bluetooth tag can work for weeks.

The 2015 Hackaday Prize is sponsored by:

Circuit Stickers


One of our tipsters just sent an interesting crowd funding project our way. They’re called Circuit Stickers and are a very creative way to get basic electronics into children’s hands through arts and crafts.

The project is the brainchild of [Bunnie] and [Jie Qi]. [Bunnie] is a hacker, and a Director of Studio Kosagi, a small manufacturing outfit in Singapore. [Jie] on the other hand is a PhD student at the MIT Media Lab, who focuses her research on combining electronics and programming with arts and crafts. They came up with this idea to bridge the gap that exists between electronics and the arts, and the stickers are a great start. They allow anyone to learn basic electronics in a very easy and friendly way, using skills we all learned as children, drawing and sticking stickers on everything.

The current offering includes LED stickers, effects stickers (to control the LEDs), sensors, microcontrollers, and even breakout boards. They are all in sticker form, and can be connected together using  conductive fabric, thread, carbon-based paint, copper tape, pencil graphite, and really, anything conductive. They have already manufactured thousands of the stickers and everything is working as designed, so the crowdfunding campaign isn’t to raise funds to continue research, or even to start their company. It’s more of getting it out there, and getting these stickers into children’s hands to raise the next generation of hackers from a young age.

The video after the break gives a great overview of the project, and if anything we think it’ll give you some great ideas on children’s electronics projects.

Continue reading “Circuit Stickers”