Month: May 2016

Hand design from scan data and 3D modeling.

16 more images in gallery

It all started because Amy Karle wanted to grow her own exoskeleton. But after experimenting with 3D printing bones during an artist residency program through Autodesk's Pier 9 workshop in San Francisco, she set her sights on something a little smaller and more intimate. She decided to grow a human hand.

Karle has a lot of experience with human limbs because she volunteers with a nonprofit group that 3D prints prosthetic arms for children and makes its designs available for free. She also works on medical instruments, and told Ars that she's fascinated by objects that go inside the body, as well as how parts of our bodies can live outside us. With her new project "Regenerative Reliquary," currently on display at the Pier 9 space in San Francisco, she's brought all her obsessions together to create an actual hand grown from human stem cells on a 3D printed trellis.

Working with bioscientist Chris Venter in Pier 9's Bio/Nano Lab and Autodesk materials scientist John Vericella, Karle designed a bone trellis in CAD based on the dimensions of her own hand. This trellis, which looks like a cross between a skeleton and a piece of jewelry, is made from pegda, a hydrogel used as a cellular growth medium in petri dishes and elsewhere. Its structure is modeled on the trabecular structure of the spongy microlattices within bone that make it flexible. For several weeks, she and her collaborators worked on 3D printing a pegda trellis on the Ember printer that would hold together inside a bioreactor where cells could grow. In the gallery above, you can see the hand inside a bioreactor, as well as what the trellis looks like under magnification. Next, she needed a cell line to grow on the trellis. Karle told Ars that she'd hoped at first to harvest her own stem cells, or to use cancer cells from a mouse. But both of those options raised safety issues, so she and the scientists settled for using human mesenchymal stem cells, extracted from bone marrow (of course you can order human stem cells online). Currently, Karle is culturing the cells, and the next step in her project will be to grow them on the hand trellis. Once the project is complete, Karle will post instructions on how to build your own hand on the DiY site Instructables.

Delphi has been testing its 48V mild hybrid system in this Honda Civic turbodiesel. (credit: Delphi)

It's clear that we need to make our passenger vehicles a lot more efficient if we want to avoid some of the very worst effects of climate change. And it's also becoming increasingly clear that diesel—which was once looked at in places like Europe as a panacea for this problem—might not be quite so groovy, what with rampant emissions cheating in the auto industry. Delphi, a major vehicle component supplier, thinks it has a real solution to help us with this, in the form of 48V "mild hybrids."

Climate change is such a big problem that even Donald Trump (who says he doesn't believe in it, publicly) is spending money to defend his properties from sea level rise. Although passenger vehicle emissions are only part of the carbon emission problem, in the US, Europe, and China regulators are taking the problem seriously, with increasingly strict fuel efficiency targets for all new cars. Here in the US, car makers have until 2025 to double their average fuel economy to 54.5mpg, but things are even tighter abroad. China has set 2020 for its deadline, by which time manufacturer averages have to be down to 117 grams of CO₂ per km driven, and the following year the EU requires fleet averages of just 95g/km. And along with those targets come hefty financial penalties for missing them.

Several years ago, we took a deep dive into some of the technologies that automakers are looking at to get themselves out of this bind. These features included variable valve timing, small capacity turbocharged engines, gasoline and diesel direct injection, cylinder deactivation, and stop-start functions. But all of those features are being widely deployed across new vehicle fleets, and it's clear that they won't be enough. Of course, there's also the wide world of electrification, like plug-in hybrid electric vehicles and battery EVs, but adoption of EVs of all stripes remains insufficient to really move the needle—even accounting for Tesla's gigantic Model 3 presales. That's where the 48V mild hybrid comes in.

(credit: Cole Marshall)

When Charter purchased Time Warner Cable and Bright House Networks, federal regulators forced the company to agree to some conditions designed to boost competition in the Internet service market. Charter, now the nation's second largest cable company behind Comcast because of the merger, is required to bring broadband of at least 60Mbps to at least 1 million homes and businesses where there's already a provider offering at least 25Mbps.

This is known as "overbuilding," something that happens infrequently enough that many Americans have only one choice for high-speed Internet. But when Charter fulfills the overbuilding requirement imposed by the Federal Communications Commission, it'll apparently do so without actually competing against other cable companies. Instead, Charter will enter the territory of phone companies like AT&T or Frontier, Charter CEO Tom Rutledge said.

Why is that? Because Charter might want to buy more cable companies later. And the FCC is less likely to approve a merger between two companies competing against each other.

Just a couple of 1.56 billion-year-old fossils from southern China. (credit: Maoyan Zhu)

The Cambrian “explosion” of life around 540 million years ago is one heck of a story, in which a huge variety of animal body plans first appear in the fossil record. But the harder we look, the more interesting and incredible the Cambrian prequels become. Now, there's a report of organisms big enough to be easily visible yet dating back to more than 1.5 billion years ago.

The fuse to the Cambrian bomb was quite long and, at the very least, had some firecrackers tied to it. Single-celled eukaryotes, organisms with a nucleus and other complex internal structures, joined the bacteria and archaea around 1.5 billion years before the Cambrian. About 60 million years before the start of the Cambrian, a considerable batch of complex organisms appeared, although their relationships to Cambrian life are contentious.

The history of multi-cellular eukaryotes in between is hard to piece together, as extraordinary luck is needed to preserve evidence of their soft cell bodies for us to find. We have a couple examples of tiny multi-cellular organisms that may have been eukaryotes, but a new discovery from a team led by Shixing Zhu of the China Geological survey adds a big one to the family. The long, flat fossils they found in 1.56 billion-year-old rocks were up to a whopping 30 centimeters long and 8 centimeters wide.