An electronic scaffold for growing cyborg tissues
To craft synthetic flesh, all you need are seed cells—stem cells or cells from a specific organ—to form the basis of the material and a scaffold of biological material, which supports the cells as they grow into tissue for patching up hearts or artificial organs. But why grow boring old biological materials when you can create cyborg ones? In a new paper published in Nature Materials, researchers describe how to make synthetic tissues that integrate electronics.
Instead of growing cells on a purely biological scaffold, these researchers used nanowires to build electronic scaffolds and then coat them with biological materials like collagen, forming hybrid scaffolds that included both tissue and technology. With these scaffolds as a base, researchers successfully formed viable cyborg tissue from seed cells, including neurons, cardiac, and smooth muscle cells. The tissue remained viable for a few weeks, but the researchers still need to conduct extended studies to see how these tissues would fare as long-term implants.
The core of the new room-temperature maser
When the laser was first invented, it was “a solution waiting for a problem,” a piece of cutting-edge technology with no applications. Today, found in everything from sensors to communications to surgery, the laser has come into its own—but it may be time to step aside and share the spotlight with its older brother, the maser.
Lasers and masers work on the same principle, amplifying light through a process called stimulated emission, except that lasers amplify visible light while masers act on microwaves. Light and microwaves are both forms of electromagnetic radiation, but microwaves have a wavelength 100,000 times greater than that of visible light. But although the maser has been used for deep-space communications and atomic clocks, lasers have always outshone their predecessors. And masers have only themselves to blame, as these finicky devices require extreme conditions like vacuum or cold temperatures. Now, however, researchers have finally produced a maser that functions while surrounded by air at room temperature.
An 1865 painting by Frederic Edwin Church, possibly inspired by the aurora of 1859.
On September 1, 1859, the sky erupted in color: “alternating great pillars, rolling cumuli shooting streamers, curdled and wisped and fleecy waves—rapidly changing its hue from red to orange, orange to yellow, and yellow to white, and back in the same order to brilliant red,” read a New York Times account. This was the aurora seen around the world.
Meanwhile, the telegraph operators were perplexed to find that the system suddenly failed. None of the lines worked, and telegraph paper spontaneously caught on fire. The aurora and disconnected telegraphs were both the working of the largest solar storm recorded in history.
What’s the News: If two South Korean researchers have their way, the days of needing specialized equipment to test whether someone has strep, the flu, or other common illnesses may soon be numbered. The pair want to check for disease markers in a tiny drop of a bodily fluid by pressing it against a touchscreen, so your diagnosis could come straight from your smart phone. While there’s no app for that yet, the scientists recently finished a proof-of-concept study showing that a touchscreen could differentiate between various concentrations of bacterial DNA—a first step towards diagnosing your disease by spitting on your iPad.
What’s the News: Metamaterials could improve wireless power transfer, letting us one day charge our devices without the hassle of cords and wires, says a study published last week in Physical Review B. While wireless power transfer already works to for tiny amounts of energy, metamaterials could theoretically be used to safely and efficiently boost the technique to handle more power, such as microwaves and lasers.
What’s the News: The foundation of modern electronics, silicon transistors are miniature on/off switches that regulate electric current. This week, Intel demonstrated a new transistor design that’s being hailed by Intel as one of the most radical developments in transistors since the advent of integrated circuits of the 1950s. By adding tiny, vertical fins to normally flat transistors, Intel’s new Tri-Gate transistor allows for faster, smaller, and lower-voltage computer chips. “We’ve been talking about these 3-D circuits for more than 10 years, but no one has had the confidence to move them into manufacturing,” chip-manufacturing specialist Dan Hutcheson told The Wall Street Journal. Read More
What’s the News: Scientists have discovered a new technique for linking semiconducting tubes with mouse nerve cell tendrils: They let the cells do the work for them. After creating biologically friendly semiconductor tubes, they found that nerve cells’ tendril-like axons didn’t shy away. “They seem to like the tubes,” University of Wisconsin-Madison biomedical engineer Justin Williams told Science News. This represents a step toward new technology involving computer-brain networks.
How the Heck: The trick was to create tubes of layered germanium and silicone (which insulate the nerve’s electrical signals) that were big enough for the nerve cell’s threadlike projections to enter but too small for the cell body: When seeded with live mouse nerve cells, the only way the cells could interact with the tubes was be sending tendrils into it—which is just what they did.
What’s the Context:
Not So Fast: The researchers don’t yet know whether the connected nerves are actually talking with each other.
Next Up: Now they want to hook the tubes to voltage sensors that can “listen” to the cells communicating with each other. If successful, this could lead to new drug tests where doctors can actually measure how nerve cells respond to certain types of drugs, leading to further innovations in the battle against neurological diseases like Parkinson’s.
Image: Minrui Yu, University of Wisconsin–Madison
Reference: “Semiconductor Nanomembrane Tubes: Three-Dimensional Confinement for Controlled Neurite Outgrowth” Minrui Yu et al. DOI: 10.1021/nn103618d
When experts talk about discarding today’s silicon-based computer chips and building next-generation electronics out of new materials, they’re usually talking about graphene, and for good reason–the one-atom-thick layers of carbon can behave like semiconductors and have already been used in experimental transistors. But researchers from a Swiss lab think they have a material that can trump both silicon and graphene. World, meet molybdenite.
The researchers from École Polytechnique Fédérale de Lausanne (EPFL) note that the mineral looks similar to mica, and has a layered molecular structure that allows it to sheer off easily into thin sheets.
Molybdenite, the researchers said, is abundant in nature and is currently used in steel alloys and in lubricants, but it has not previously been studied for use in electronics. “It’s a two-dimensional material, very thin and easy to use in nanotechnology. It has real potential in the fabrication of very small transistors, light-emitting diodes (LEDs) and solar cells,” said EPFL Professor Andras Kis, adding that molybdenite (MoS2) is far more compact than silicon, while still allowing electrons to circulate freely. [PC Pro]
The Story of Electronics has made its debut today (teaser above), following the form of the original Story of Stuff video in 2007. The Story of Stuff, written and narrated by Annie Leonard, created waves of discussion about the environment and consumption in classrooms, homes, and workplaces around the country.
She [created the movie], she said, after tiring of traveling often to present her views at philanthropic and environmental conferences. She attributes the response to the video’s simplicity. “A lot of what’s in the film was already out there,” Ms. Leonard said, “but the style of the animation makes it easy to watch. It is a nice counterbalance to the starkness of the facts.” [New York Times]
The new electronics chapter takes a step beyond the original video’s take on the manufacturing process and consumerism to explain the concept of planned obsolescence, the idea that our electronics are being “designed for the dump”–that is, to be cheaply replaceable as quickly as possible. The video makes a point that these cheap electronics come with hidden costs–to factory workers, people in unsafe electronics recycling facilities, and to the environment.
In an exciting pilot study, blind people equipped with microchips in their retinas were able to see again–at least dimly–and were able to make out shapes.
Ed Yong explains how the experiment helped a study participant named Miikka:
In people like Miikka with retinitis pigmentosa, the light-detecting cells of the retina break down with age. Eberhart Zrenner and a team of German scientists have designed a chip that does the same job as these defunct cells. Just a few millimetres across, it contains 1,500 light-detecting diodes that detect light and convert it into a current. The brighter the light that hits the chip, the stronger the current it puts out. The current is delivered directly to the bipolar cells, which would normally transmit the signals from the retina’s actual light detectors.
Find out more about how the technology works and get the full story on Miikka and his fellow experiment subjects at Not Exactly Rocket Science. And check out the videos of Miikka trying out his new eyes below.
Not Exactly Rocket Science: Retinal Implant Partially Restores Sight in Blind People
80beats: The Eyes Have It: Lab-Made Corneas Restore Vision
80beats: Stem Cell Treatment Lets Those With Scorched Corneas See Again
80beats: The Part of the Brain That Lets the Blind See Without Seeing
80beats: Gene Therapy Cures Color Blindness in Monkeys