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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Who’d Have Guessed? Graphene Is Strange!

February 7, 2025 by Al Williams 3 Comments

Graphene always sounds exciting, although we aren’t sure what we want to do with it. One of the most promising features of the monolayer carbon structure is that under the right conditions, it can superconduct, and some research into how that works could have big impacts on practical superconductor technology.

Past experiments have shown that very cold stacks of graphene (two or three sheets) can superconduct if the sheets are at very particular angles, but no one really understands why. A researcher at Northeaster and another at Harvard realized they were both confused about the possible mechanism. Together, they have started progressing toward a better description of superconductivity in graphene.

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Synthesis Of Goldene: Single-Atom Layer Gold With Interesting Properties

April 25, 2024 by Maya Posch 16 Comments

The synthesis of single-atom layer versions of a range of atoms is currently all the hype, with graphene probably the most well-known example of this. These monolayers are found to have a range of mechanical (e.g. hardness), electrical (conduction) and thermal properties that are very different from the other forms of these materials. The major difficulty in creating monolayers is finding a way that works reliably and which can scale. Now researchers have found a way to make monolayers of gold – called goldene – which allows for the synthesis of relatively large sheets of this two-dimensional structure.

In the research paper by [Shun Kashiwaya] and colleagues (with accompanying press release) as published in Nature Synthesis, the synthesis method is described. Unlike graphene synthesis, this does not involve Scotch tape and a stack of graphite, but rather the wet-etching of Ti₃Cu₂ away from Ti₃AuC₂, after initially substituting the Si in Ti₃SiC₂ with Au. At the end of this exfoliation procedure the monolayer Au is left, which electron microscope studies showed to be stable and intact. With goldene now relatively easy to produce in any well-equipped laboratory, its uses can be explored. As a rare metal monolayer, the same wet exfoliation method used for goldene synthesis might work for other metals as well.

Molybdenene whiskers. (Credit: Sahu et al., 2023)

Introducing Molybdenene As Graphene’s New Dirac Matter Companion

November 12, 2023 by Maya Posch 9 Comments

Amidst all the (well-deserved) hype around graphene, it’s important to remember that its properties are not unique to carbon. More atoms can be coaxed into stable 2-dimensional configuration, with molybdenene previously theoretically possible. This is now demonstrated by Tumesh Kumar Sahu and colleagues in a recent Nature Nanotechnology article, through the manufacturing of a 2D molybdenum-based material which they showed to be indeed molybdenene. Essentially, this is a 2D lattice of molybdenum atoms, a configuration in which it qualifies as Dirac matter, just like graphene. For those of us unfamiliar with Dirac materials, this gentle introduction by Jérôme Cayssol in Comptes Rendus Physique might be of use.

Manufacturing process of molybdenene. (Credit: Sahu et al., 2023)

In order to create molybdenene, the researchers started with molybdenum disulfide (MoS₂), which using a microwave-assisted field underwent electrochemical transformation into whiskers that when examined turned out to consist out of monolayers of Mo. The sulfur atoms were separated using a graphene sheet. As is typical, molybdenene sheets were exfoliated using Scotch tape, in a process reminiscent of the early days of graphene research.

Much like graphene and other Dirac materials, molybdenene has many potential uses as a catalyst, as cantilever in scanning electron microscope (SEM) tips, and more. If the past decades of research into graphene has demonstrated anything, it is that what once seemed more of a novelty, suddenly turned out to have endless potential in fields nobody had considered previously. One of these being as coatings for hard disk platters, for example, which has become feasible due to increasingly more efficient ways to produce graphene in large quantities.

$1 Graphene Sensor Identifies Safe Water

August 29, 2023 by Al Williams 15 Comments

If you live in a place where you can buy Arduinos and Raspberry Pis locally, you probably don’t spend much time worrying about your water supply. But in some parts of the world, it is nothing to take for granted, bad water accounts for as many as 500,000 deaths worldwide every year. Scientists have reported a graphene sensor they say costs a buck and can detect dangerous bacteria and heavy metals in drinking water.

The sensor uses a GFET — a graphene-based field effect transistor to detect lead, mercury, and E. coli bacteria. Interestingly, the FETs transfer characteristic changes based on what is is exposed to. We were, frankly, a bit surprised that this is repeatable enough to give you useful data. But apparently, it is especially when you use a neural network to interpret the results.

What’s more, there is the possibility the device could find other contaminants like pesticides. While the materials in the sensor might have cost a dollar, it sounds like you’d need a big equipment budget to reproduce these. There are silicon wafers, spin coating, oxygen plasma, and lithography. Not something you’ll whip up in the garage this weekend.

Still, it is interesting to see a FET used this way and a cheap way to monitor water quality would be welcome. Using machine learning with water sensors isn’t a new idea. Of course, the sensor is one part of the equation. Monitoring is the other.

Easy Graphene Production With A Laser Engraver

May 20, 2023 by Al Williams 13 Comments

Graphene isn’t easy to produce at scale. But making small batches of graphene is doable in a few ways. [Robert Murray-Smith] decided to try producing “flash graphene.” This requires a big capacitor bank that is moderately expensive, so he decided to explain a different technique he read about using an ordinary laser cutter. Check it out in the video below.

We were a little disappointed that he didn’t actually make any graphene this time. He has, however, used other methods in other videos to create some type of graphene. In fact, he has many similar videos going back quite a ways as well as applications with concrete, capacitors, and more. We understand that this method doesn’t produce monolayer graphene, but actually creates a graphene “foam” with interesting properties. [Robert] talks about recent papers that show you can grow graphene on things other than Kapton tape using this method.

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Noninvasive Sensors For Brain–Machine Interfaces Based On Micropatterned Epitaxial Graphene

April 15, 2023 by Maya Posch 4 Comments

As fun as brain-computer interfaces (BCI) are, for the best results they tend to come with the major asterisk of requiring the cutting and lifting of a section of the skull in order to implant a Utah array or similar electrode system. A non-invasive alternative consists out of electrodes which are placed on the skin, yet at a reduced resolution. These electrodes are the subject of a recent experiment by [Shaikh Nayeem Faisal] and colleagues in ACS Applied NanoMaterials employing graphene-coated electrodes in an attempt to optimize their performance.

Impedance values of eight-channel FEG and eight-channel HPEG sensor systems placed on the occipital area of the head. (Faisal et al., 2023)

Although external electrodes can be acceptable for basic tasks, such as registering a response to a specific (visual) impulse or for EEG recordings, they can be impractical in general use. Much of this is due to the disadvantages of the ‘wet’ and ‘dry’ varieties, which as the name suggests involve an electrically conductive gel with the former.

This gel ensures solid contact and a resistance of no more than 5 – 30 kΩ at 50 Hz, whereas dry sensors perform rather poorly at >200 kΩ at 50 Hz with worse signal-to-noise characteristics, even before adding in issues such as using the sensor on a hairy scalp, as tends to be the case for most human subjects.

In this study, they created electrode arrays in a number of configurations, each of which used graphene as the interface material. The goal was to get a signal even through human hair — such as on the back of the head near the visual cortex — that would be on-par with wet electrodes. The researchers got very promising results with hex-patterned epitaxial graphene (HEPG) sensors, and even in this early prototype stage, the technique could offer an alternative where wet electrodes are not an option.

While the subject is complex, brain-computer interfaces don’t have to be the sole domain of research laboratories. We recently covered an open hardware Raspberry Pi add-on that can let you experiment with detecting and filtering biosignals from the comfort of your own home.