Make DIY Conductive, Biodegradable String Right In Your Kitchen

March 28, 2025 by Donald Papp 2 Comments

[ombates] shares a step-by-step method for making a conductive bio-string from scratch, no fancy equipment required. She demonstrates using it to create a decorative top with touch-sensitive parts, controlling animations on an RGB LED pendant. To top it off, it’s even biodegradable!

The string is an alginate-based bioplastic that can be made at home and is shaped in a way that it can be woven or knitted. Alginate comes primarily from seaweed, and it gels in the presence of calcium ions. [ombates] relies on this to make a goopy mixture that, once extruded into a calcium chloride bath, forms a thin rubbery length that can be dried into the strings you see here. By adding carbon to the mixture, the resulting string is darkened in color and also conductive.

There’s no details on what the actual resistance of a segment of this string can be expected to measure, but while it might not be suitable to use as wiring it is certainly conductive enough to act as a touch sensor in a manner similar to the banana synthesizer. It would similarly be compatible with a Makey Makey (the original and incredibly popular hardware board for turning household objects into touch sensors.)

What you see here is [ombates]’ wearable demonstration, using the white (non-conductive) string interwoven with dark (conductive) portions connected to an Adafruit Circuit Playground board mounted as an LED pendant, with the conductive parts used as touch sensors.

Alginate is sometimes used to make dental molds and while alginate molds lose their dimensional accuracy as they dry out, for this string that’s not really a concern. If you give it a try, visit our tip line to let us know how it turned out!

Wearable Computing Goes Woven, Wireless, And Washable

March 24, 2025 by Donald Papp 5 Comments

Sometimes we come across a wild idea that really tries to re-imagine things, and re-conceiving wearable computing as a distributed system of “fiber computers” embedded into textiles is definitely that. The research paper presents fully-functional fiber computers and sensors that are washable, weave-able, wireless, and resist both stretching and bending.

The research paper with all the details is behind a paywall at this time, but we’ll summarize the important parts that are likely to get a hacker’s mind working.

Each fiber strand (like the one shown here) is a self-contained system. Multiple fibers can communicate with one another wirelessly to create a network that, when integrated into garments, performs tasks like health and activity monitoring while using very little power. And what’s really interesting about these fibers is their profound lack of anything truly exotic when it comes to their worky bits.

The inner components of a fiber computer are pretty recognizable: each contains a surface-mount microcontroller, LEDs, BLE (Bluetooth Low Energy) radio, light sensor, temperature sensor, accelerometer, and photoplethysmography (PPG) sensor for measuring blood volume changes through skin. Power is supplied by a separate segment containing a tiny cylindrical lithium-polymer battery, with a simple plug connector. It’s a tiny battery, but the system is so low-power that it still provides hours of operation.

If there’s a secret sauce, it’s in the fabrication. The first step is stretching a system into a long, thin circuit. Each component is nested onto a small piece of flex PCB that acts a little like a breakout board, and that flex PCB gets rolled around each component to make as tiny a package as possible. These little payloads are connected to one another by thin wires, evenly spaced to form a long circuit. That circuit gets (carefully!) sealed into a thermoformed soft polymer and given an overbraid, creating a fiber that has a few lumps here and there but is nevertheless remarkably thin and durable. The result can be woven into fabrics, worn, washed, bent, and in general treated like a piece of clothing.

Closeups of components that make up a single strand of “fiber computer”.

Multiple fibers are well-suited to being woven into clothing in a distributed way, such as one for each limb. Each fiber is self-contained but communicates with its neighbors using a BLE mesh, or transmitting data optically via embedded LEDs and light sensors. Right now, such a distributed system has been shown to be able to perform health monitoring and accurately classify different physical activities.

We’ve seen sensors directly on skin and transmitting power over skin, but this is a clever fusion of conventional parts and unconventional design — wearable computing that’s not just actually wearable and unobtrusive, but durable and even washable.

Pick Up A Pebble Again

March 19, 2025 by Jenny List 38 Comments

A decade ago, smartwatches were an unexplored avenue full of exotic promise. There were bleeding-edge and eye-wateringly expensive platforms from the likes of Samsung or Apple, but for the more experimental among technophiles there was the Pebble. Based on a microcontroller and with a relatively low-resolution display, it was the subject of a successful crowdfunding campaign and became quite the thing to have. Now long gone, it has survived in open-source form, and now if you’re a Pebble die-hard you can even buy a new Pebble. We’re not sure about their choice of name though, we think calling something the “Core 2 Duo” might attract the attention of Intel’s lawyers.

The idea is broadly the same as the original, and remains compatible with software from back in the day. New are some extra sensors, longer battery life, and an nRF52840 BLE microcontroller running the show. It certainly captures the original well, however we’re left wondering whether a 2013 experience still cuts it in 2025 at that price. We suspect in that vein it would be the ideal compliment to your game controller when playing Grand Theft Auto V, another evergreen 2013 hit.

We look forward to seeing where this goes, and we reported on the OS becoming open source earlier this year. Perhaps someone might produce a piece of open source hardware to do the same job?

“Glasses” That Transcribe Text To Audio

March 19, 2025 by Lewin Day 10 Comments

Glasses for the blind might sound like an odd idea, given the traditional purpose of glasses and the issue of vision impairment. However, eighth-grade student [Akhil Nagori] built these glasses with an alternate purpose in mind. They’re not really for seeing. Instead, they’re outfitted with hardware to capture text and read it aloud.

Yes, we’re talking about real-time text-to-audio transcription, built into a head-worn format. The hardware is pretty straightforward: a Raspberry Pi Zero 2W runs off a battery and is outfitted with the usual first-party camera. The camera is mounted on a set of eyeglass frames so that it points at whatever the wearer might be “looking” at. At the push of a button, the camera captures an image, and then passes it to an API which does the optical character recognition. The text can then be passed to a speech synthesizer so it can be read aloud to the wearer.

It’s funny to think about how advanced this project really is. Jump back to the dawn of the microcomputer era, and such a device would have been a total flight of fancy—something a researcher might make a PhD and career out of. Indeed, OCR and speech synthesis alone were challenge enough. Today, you can stand on the shoulders of giants and include such mighty capability in a homebrewed device that cost less than $50 to assemble. It’s a neat project, too, and one that we’re sure taught [Akhil] many valuable skills along the way.

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Smartwatches Could Flatten The Curve Of The Next Pandemic

March 4, 2025 by Navarre Bartz 72 Comments

While we’d like to think that pandemics and lockdowns are behind us, the reality is that a warming climate and the fast-paced travel of modern life are a perfect storm for nasty viruses. One thing that could help us curb the spread of the next pandemic may already be on your wrist.

Researchers at Aalto University, Stanford University, and Texas A&M have found that the illness detection features common to modern smartwatches are advanced enough to help people make the call to stay home or mask up and avoid getting others sick. They note we’re already at 88% accuracy for early detection of COVID-19 and 90% for the flu. Combining data from a number of other studies on smartwatch accuracy, epidemiology, behavior, and biology, the researchers were able to model the possible outcomes of this early detection on the spread of future diseases.

“Even just a 66-75 percent reduction in social contacts soon after detection by smartwatches — keeping in mind that that’s on a par with what you’d normally do if you had cold symptoms — can lead to a 40-65 percent decrease in disease transmission compared to someone isolating from the onset of symptoms,” says Märt Vesinurm.

We’ve got you covered if you’re looking for a smartwatch that looks a bit like a hospital wristband and we’ve also covered one that’s alive. That way, you’ll have a slimy friend when you’re avoiding other humans this time around. And when it’s time to develop a vaccine for whatever new bug is after us, how do MRNA vaccines work anyway?

Cheap Hackable Smart Ring Gets A Command Line Client

March 4, 2025 by Arya Voronova 17 Comments

Last year, we’ve featured a super cheap smart ring – BLE, accelerometer, heart sensor, and a battery, all in a tiny package that fits on your finger. Back when we covered it, we expected either reverse-engineering of stock firmware, or development of a custom firmware outright. Now, you might be overjoyed to learn that [Wesley Ellis] has written a Python client for the ring’s stock firmware.

Thanks to lack of any encryption whatsoever, you can simply collect the data from your ring, no pairing necessary, and [Wesley]’s work takes care of the tricky bits. So, if you want to start collecting data from this ring right now, integrate it into anything you want, such as your smart home or exoskeleton project, this client is enough. A few firmware secrets remain – for instance, the specific way that the ring keep track of day phases, or SPO2 intricacies. But there’s certainly enough here for you to get started with.

This program will work as long as your ring uses the QRing app – should be easy to check right in the store listing. Want to pick up the mantle and crack open the few remaining secrets? Everything is open-source, and there’s a notepad that follows the OG reverse-engineering journey, too. If you need a reminder on what this ring is cool for, here’s our original article on it.

Graphene Tattoos: The Future Of Continuous Health Monitoring?

February 16, 2025 by Heidi Ulrich 22 Comments

In the near future, imagine a world where your health is continuously monitored, not through bulky devices but through an invisible graphene tattoo. Developed at the University of Massachusetts Amherst, these tattoos could soon detect a range of health metrics, including blood pressure, stress levels, and even biomarkers of diseases like diabetes. This technology, though still in its infancy, promises to revolutionize how we monitor health, making it possible to track our bodies’ responses to everything from exercise to environmental exposure in real-time.

Graphene, a single layer of carbon atoms, is key to the development of these tattoos. They are flexible, transparent, and conductive, making them ideal for bioelectronics. The tattoos are so thin and pliable that users won’t even feel them on their skin. In early tests, graphene electronic tattoos (GETs) have been used to measure bioimpedance, which correlates with blood pressure and other vital signs. The real breakthrough here, however, is the continuous, non-invasive monitoring that could enable early detection of conditions that usually go unnoticed until it’s too late.

While still requiring refinement, this technology is advancing rapidly. Graphene still amazes us, but it’s no longer just science fiction. Soon, these tattoos could be a part of everyday life, helping individuals track their health and enabling better preventative care. Since we’re hackers out here – but this is a far fetch – combining this knowledge on graphene production, and this article on tattooing with a 3D printer, could get you on track. Let us know, what would you use graphene biosensors for?

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