A real neural network

Paul Raven @ 23-03-2011

And today’s award for Endearingly Punning Post Headline of the Day goes to my good buddy m1k3y, who has graced grinding.be with a piece titled “Scientists train mouse nerves to grow through series of tubes“. The source for it is this Science News post, which explains how some clever folk have managed to encourage mouse neurons to grow their way along microscopic tubes of semiconductor material, making a crude self-assembling network. But don’t panic: there’s been no firing up of cyber-rodent self-awareness. Yet.

When the team seeded areas outside the tubes with mouse nerve cells the cells went exploring, sending their threadlike projections into the tubes and even following the curves of helical tunnels, the researchers report in an upcoming ACS Nano.

“They seem to like the tubes,” says biomedical engineer Justin Williams, who led the research. The approach offers a way to create elaborate networks with precise geometries, says Williams. “Neurons left to their own devices will kind of glom on to one another or connect randomly to other cells, neither of which is a good model for how neurons work.”

At this stage, the researchers have established that nerve cells are game for exploring the tiny tubes, which seem to be biologically friendly, and that the cell extensions will follow the network to link up physically. But it isn’t clear if the nerves are talking to each other, sending signals the way they do in the body. Future work aims to get voltage sensors and other devices into the tubes so researchers can eavesdrop on the cells. The confining space of the little tunnels should be a good environment for listening in, perhaps allowing researchers to study how nerve cells respond to potential drugs or to compare the behavior of healthy neurons with malfunctioning ones such as those found in people with multiple sclerosis or Parkinson’s.

No radical melding of meat and machine, then, but I suppose the coexistence of living cells and semiconductors has to be a step in that direction…


Paul Raven @ 14-12-2010

Organic computing, anyone? Ars Technica reports on a paper published in Nature, wherein the authors describe the creation of bacterial colonies that can act as logic gates:

The key to the new work is stretches of DNA that act as logical OR and NOR functions. Both of them rely on small stretches of DNA called promoters that control the activity of nearby genes. In this case, the authors used promoters that activate nearby genes in response to simple chemicals (arabinose and tetracycline for these two promoters). By putting both promoters next to a reporter gene, the system acted as an OR gate: when either of the chemicals was present, the reporter was on.


the authors set up small clusters of bacterial colonies (small lumps of genetically identical cells). Each colony had a single logic gate (the authors used NOR, OR, and NOT gates). Depending on the arrangement of the colonies, each one could signal to only one or two neighbors, and each could only take input from one or two. The authors demonstrated a functional XOR gate built from four colonies, showing that all logical functions can be built from similar combinations.

The nice thing about using populations of cells is that this averages out some of the chaotic behavior typical of systems based on single cells. At a minimum, the systems they tested showed a five-fold difference between their on and off states. The downside is that, relative to a single cell, these systems are huge. The authors suggest that it might be possible to adapt their system to single cells, but it’s not clear that the same sort of performance could be maintained.

Boole meets biology. Maybe one day we’ll grow computers instead of building them from silicon slices…

Energy independence for sewage-eating robot

Paul Raven @ 22-07-2010

This story’s all over the place, at venues as diverse as Hack-A-Day and Mike Anissimov’s blog… and with good reason. Here’s the lede from PhysOrg:

UK researchers have developed an autonomous robot with an artificial gut that enables it to fuel itself by eating and excreting. The robot is the first bot powered by biomass to be demonstrated operating without assistance for several days. Being self-sustaining would enable robots of the future to function unaided for long periods.

Yup, you read that right – this machine eats a kind of organic slurry, digests the nutrients in it and then craps out the waste. Not quite so elegant (or do I mean sinister?) as the proposed rat-eating household bot we mentioned a while back, eh?

Joking aside, this is quite a big deal – energy-autonomous machines could do all sorts of amazing things, and some scary ones too. It also stirs up the same arguments about “artificial life” as the Venter announcement, albeit coming from a very different angle: if I remember my GCSE biology right, eating and excreting are two pillars of the scientific definition of biological life, and there’s a machine that does both as well as being capable of independent movement. Interesting times, people, interesting times.

Speaking of sewage and energy, we could probably be getting some of our household wattage from human waste, and there’s a pilot scheme for biomethane recapture from sewage here in the UK at the moment. But gas is tricky and dangerous to store and pipe – why not cut out the middle man and just get the energy out of the sewage directly? To be truthful, there’s still a middle man… billions of them, in fact. Apparently certain nanoparticle coatings applied to graphite anodes in sewage tanks encourage certain bacteria to proliferate, eating sewage and releasing electrons all the while. Your biowaste gets cleaned up, and you produce electricty at the same time! Sounds almost too good to be true… but they’ve got it working in a lab environment, so you never know.

Bacterial biker jackets and after-market parts for people

Paul Raven @ 12-07-2010

This year seems like it’ll be the one where the mainstream starts talking about custom-made replacement organs as something more than science fiction. A few weeks back we heard about the rat who got a new set of lab-grown lungs; this week, Wired is running a photo-essay on bioprinting that’s a must-see for anyone who wants to be able to write a plausible description of the working environment of a contemporary Frankenstein.

Bioreactor - image credited to Dave Bullock/Wired.com

Meanwhile [via BoingBoing] Ecouterre reports on UK-based designer Suzanne Lee, who’s been using bacteria to grow an entire range of clothing from a rather mundane starting point – sweetened green tea. The end results are made entirely of cellulose, though they look (to me at least) like the skin of something that still slinks through radiation-soaked cities long after the posthumans abandoned Earth for the new terrain at the top of the gravity well…

Bio-couture jacket by Suzanne Lee

Organic ain’t yer only option, though, no sir. 3D printing means one-off custom designs of mechanical prosthetic limb can be made for amputees or other folk with different levels of physical ability… and not just for us longpigs, either, as Oscar the cyborg cat ably demonstrates. 3D printing is still an unevenly distributed piece of the future, of course, but it’s spreading fast; Ponoko have just set up their first 3D print hub here in the UK, and if they can afford to do that in the current economic climate, the business model must have something going for it, right?

It’s interesting to see the organic and inorganic racing along in parallel like this; it doesn’t take a genius to see the possibilities of the two streams converging somewhere down the line, though I’d guess that’s a good few decades off from the present day. What’s interesting to me about these phenomena is the way they seem to be an end-game expression of the desire for individuality and customisation; at the moment, price will keep all but those with a serious need for these products out of the market, but as prices fall, everything will become bespoke, unique, a one-off. Which is kind of ironic if you think about it: through the total ubiquity of mechanised manufacture, we’re actually putting an end to mass production.

Organic food proven to be better for you

Tomas Martin @ 29-10-2007

Peppers such as these may be better for you grown organicallyWith the organic food market growing and growing, it’s easy to wonder just how much difference it makes. Are just paying more for the same input to our bodies? A group of food scientists grew a number of different crops and animal produce, one lot entirely organic, the other non-organic. They found that organic fruit, vegetables and especially milk had more antioxidants and healthy fatty acids. It’s interesting to note that the most technologically advanced option isn’t always the best one – future agriculture will have to combine new inventions with older techniques if it wants to hit the sweet spot of good food. Now I’m glad I got that subscription to Abel and Cole veg boxes.

[via the guardian, image by nevermind her]