I’m Rubber, You’re Glue: Icephobic Coating Repels Ice

ice

Generally-speaking, hard objects and soft objects don’t bond well together. It comes down to a principle known as ‘interfacial cavitation,’ in which one surface (the soft one) deforms under pressure, while the other (the hard one) does not -– as a result, they pop apart. Now, scientists at the University of Michigan have used that principle to develop one of the most ice-repellent coatings ever made. Its applications could range from airplane wings to car windshields to freezers. (Those are the logical applications; I imagine all kinds of unique applications will follow, as people use their imagination…)

Previously, most anti-ice coatings have been rigid and slippery, with the idea being that what repels liquid water should also repel ice. According to the U Michigan team, however, that line of thought was flawed.

“Nobody had explored the idea that rubberiness can reduce ice adhesion,” says associate professor of Materials Science and Engineering Anish Tuteja. “Ice is frozen water, so people assumed that ice-repelling surfaces had to also repel water. That was very limiting.”

Instead of creating an ice-repelling solution, the team, led by Tuteja, created a rubbery coating, made from a blend of commonly available synthetic rubbers, such as polyurethane. The resulting clear spray-on coating, while somewhat tacky to the touch, might at first seem like it would “hold onto” the ice, but the fact is that the hard ice easily releases when the soft rubber deforms -– and the hardened ice slips off the surface. All that is required is the force of gravity, or a slight breeze.

By tweaking the composition of the coating, it is possible to select for factors such as durability versus ice repellency. This means that a coating designed for airplane wings could be very durable, as high winds would already blow much of the ice away, while a coating for industrial freezers would be more repellent, allowing ice to be shed with little effort.

icephobic-coating.jpg

The coating would also find instant users in the frozen North, where keeping windshields ice free is a constant battle. Despite not being able to repel water, the rubbery coating was able to stop ice from setting on the surfaces because of the previously mentioned interfacial cavitation. As the rubbery surface changes forms when exposed to even small amounts of force, it effectively prevents ice from becoming tightly bonded to it.

Advertisements

Put Your Voice in a Pot; Pour It Out When Done

Remember those cartoons you watched as a child, where people would be speaking in a snowstorm or on a bitter cold day, and their voices would freeze, and they’d have to take them home to thaw out the words out to hear what they’d said?

Well, today, “freezing” your voice for later has a new twist. It’s not a tape recorder, but something more fun: it’s a teapot recorder. Called ‘Otopot,’ the device lets you store and then pour away your voice like water.

otopot-1

It’s a simple, and captivating, idea.

To begin a recording, you simply remove the lid on the pot. You can then record up to a minute-long message.  You could serve the rechargeable pot alongside your significant other’s cup of coffee in the morning, or place one on a child’s nightstand after he or she falls asleep at night so they have an uplifting message to greet them in the morning. Imagine your voice flowing like water…

Once the recording is heard, the recipient can listen to it repeatedly simply by removing the lid. When it’s time to erase the message, one simply tips the pot as if pouring out water and the recording vanishes. The pot can only hold one recording at a time, so it becomes a fun way to hold a very unusual form of conversation.

Sure, it’s a simple matter to leave a sticky-note message for a loved one or family member, but how much more appealing would a voice memo be, complete with verbally conveyed emotions?

Click here to see how to use the James Dyson Award-winning Otopot, and the components of the talking water jug.

otopot

Understanding that people might like to send clever messages in something other than a pot, the designers created a removable ‘Otopot core,’ which can be placed inside a birthday box or any other object with a lid.

“OTOPOT” was nominated for a grand prix and awarded 2 sponsor prizes at GUGEN 2014 (a largest competition of original electrical hardware in Japan).

Currently, the student inventors, Takeshi Katayama and Shota Kumiji, are finishing up their studies but say they plan to launch the concept via a crowdfunding campaign later this year.

Will it change the world? Likely not. Will it captivate the imagination of creative types and lovers? I would think so. It would also lead to misuse, I would think, to send mean messages instead of loving memos. In that case, I would suggest the name StinkPot.

3-D Printed Ear Bones Grow in Mice

bioprint-living-ear-11

I am neither an entrepreneur nor a technology visionary. (I had initially scoffed that Web pages would simply be glorified Yellow Page ads.) I am not an early adopter of technology. I am more a third-generation user, typically all-in once my skepticism has been allayed. (While I was content with my flip-phone with its rudimentary camera, I am THRILLED that I discovered the elegance and power of the smartphone. How did we ever live without an iPhone?)

Needless to say, I scoffed at the idea of 3D printing. So you can print 3D puzzles, big deal. So you can print a model tower for an architecture presentation, big whoop. Oh, me. I am so NOT a visionary!

Today’s blog is on how 3D printing is changing science and medicine, one tiny ear bone at a time.

According to Gizmag.com, 3D printed tissues and organs have shown real potential in addressing shortages of available donor tissue for people in need of transplants, but the biggest obstacle to success has been having them take root and survive after implantation.

But in an epic life-changing success, researchers at Wake Forest Baptist Medical Center have used with a newly-developed 3D printer to produce human-scale muscle structures that matured into functional tissue after being implanted into animals.

Researchers have been exploring bioprinting as a means of replacing damaged tissue for several years now. The difficulty in replicating the complexities of human tissue has been extremely difficult, however, with scientists testing the waters with specialized bio-inks and various purpose-built printers in an effort to produce usable, engineered tissue. Every failure is a success, though, in the search for the perfect “ink” for such enterprises.

After more than a decade, researchers at Wake Forest Baptist Medical Center are engineering structures of adequate size and strength to implant in the human body, using the team’s Integrated Tissue and Organ Printing System (ITOP), which is claimed to overcome the limitations of previous bioprinting approaches.

It spouts water-based gels that contain the cells, along with biodegradable polymers arranged in a latticed pattern and a temporary outer structure.

bioprint-living-ear-4

The water-based gels were optimized to promote cell growth and health. This, combined with micro-channels that allow nutrients and oxygen from the body to permeate the structure, allows the system to remain alive while it develops a system of blood vessels.

To demonstrate its capabilities when it comes to soft tissue structures, the team used the system to produce muscle tissue, implanting it in rats and finding that two weeks later it was robust enough to permit blood flow and induce nerve formation. Using human stem cells, the system also printed jaw bone fragment large enough for a facial reconstruction and implanted them in rats. Five months later, the structures had matured into vascularized bone tissue.

bioprint-living-ear-12

Previously, engineered tissue structures without ready-made blood cells needed to be smaller than 200 microns in order for the cells to survive, but this new approach solves that problem. The researchers used ITOP to produce baby-sized ear structures measuring 1.5 in (3.8 cm) long, which were implanted under the skin of mice in the lab and went on to show signs of vascularization one and two months later.

Further adding to ITOP’s potential is its ability to take data from CT or MRI scans and make individually designed (bespoke) tissue for patients. So if a patients is missing a particular piece of tissue, such as a section of ear or nose, for example, the system could theoretically reproduce a precise replica.

“This novel tissue and organ printer is an important advance in our quest to make replacement tissue for patients,” says Anthony Atala, senior author on the study. “It can fabricate stable, human-scale tissue of any shape. With further development, this technology could potentially be used to print living tissue and organ structures for surgical implantation.”

The researchers will continue to explore the approach to track longer term results. Their current study is published in the journal Nature Biotechnology.

Technology limited only by imagination. H.G. Wells and Mary Shelley, what do you think? Any ideas? And Edward Scissorhands, ready for a makeover?

Next-Gen Football Helmets

The up-and-coming professional football player Chris Borland, of the San Francisco 49ers, is now leaving the sport out of concern that a career in football would increase his risk of brain disease. But what types of neurological problems have been linked with football, and how might these arise?

On Monday (March 16), Borland announced he was retiring from football after studying the link between football head injuries and degenerative brain disease, and discussing his decision with friends, family members, concussion researchers, and teammates, according to ESPN.

The NFL is doing what it can to solve its head trauma issue through an ongoing evaluation and revision of its rules. Rules are changing regarding definition of “vicious hit,” and guidelines are being adopted to protect players, both offensive and defensive.

But certainly, one aspect of the game that must change, especially for younger players who haven’t yet learned to protect themselves, is the design of the helmet, which must be better able to absorb an impact from other players or the ground.

Several companies are working on designs to mitigate head impacts.

University of Michigan researchers have entered the race to build a lightweight, more affordable and more effective football helmet, with a system they’ve called Mitigatium. The design incorporates three different layers that are meant to blunt some dangerous physics that today’s helmet designs ignore.

According to the researchers involved in the project, current helmets do a good job of preventing the peak force of an impact that can cause skull fractures, but they still let the brain dissipate the energy created by that hit.

helmet1
The outer two layers of the Mitigatium system takes the brunt of impact. (Credit: Evan Dougherty, Michigan Engineering)
helmet2
The inner layer of the Mitigatium system dissipates the force to better-protect the brain. (Credit: Evan Dougherty, Michigan Engineering)
helmet3
The Mitigatium is the latest football helmet designed to reduce the likelihood of players receiving traumatic brain injuries. (Credit: Steve Alvey, Michigan Engineering)

The University of Michigan researchers are focused on creating a helmet that absorbs the negative effects of impulse –- the secondary effect of an initial force or hit that may be the cause of brain injury in football players. They explain that impulse is what gives objects momentum and energy. Given the speed and weight of current football players, helmets need to be designed to block or reduce the forces of both impulse and impact.

In developing their prototype, the researchers found studies from 70 years ago that blamed impulse for damage caused by the quick, hard hits sustained in football. Yet, the results of those studies don’t seem to have made it into the long-standing designs used today.

After testing various materials in table-top collision simulators, the researchers found that the Mitigatium prototype did the best job, with a 20 percent reduction in impulse and a 30 percent reduction in peak pressure.

The three layers within the Mitigatium (seen above) include an initial layer of hard polycarbonate similar to what is used in helmet shells today, a second layer consisting of a flexible plastic, and a third layer that is described as having the consistency of dried tar. The first two layers work in tandem to reflect most of the initial force or incoming shock wave, while the third layer dissipates that force to reduce it even further. The overall effect is reduced impact to the brain.

There’s no indication as to when a helmet using Mitigatium might be put into production, since more studies and research must be completed. Other universities and companies are engaged in similar projects, including the University of Washington with its Zero1 helmet and Riddell’s Speedflex that was introduced in 2014.

Featuring an outer shell that yields upon impact like a car bumper, the Zero1 helmet is expected to be available to select NFL and NCAA football teams this spring and be worn in the 2016-17 season.

The Riddell Speedflex is designed with “crumple zones,” which will protect a player’s head upon impact. It is now generally accepted that it’s safer for vehicles to feature impact-absorbing crumple zones. With that in mind, that’s what Riddell’s new SpeedFlex helmet does … Just to be clear, the SpeedFlex doesn’t actually crumple under pressure. It does, however, have a built-in hinged rubber-padded panel located on the front near the top. In head-on collisions with other players (or the ground), this panel gives by up to a quarter of an inch (6 mm), helping to absorb the impact.

helmet6