The promise of reusable sticky things, from Post-it Notes to Blu Tack, has never quite been fulfilled. They’re just never quite as sticky the second time around, or the third. But now, a team of engineers from University of Pennsylvania and Lehigh University thinks it has an answer, inspired by one of nature’s great stickers, the humble – and slimy – snail.
Snails secrete mucus constantly, to keep their bodies from drying out, and to aid in locomotion. They also use this mucus to form an adhesive layer called an epiphragm to securely anchor themselves in place. This layer of slime finds its way into pores and irregularities of a surface where it hardens (ever tried to pull a resting snail off a wall?), but at night when the environment becomes moist and the snail decides to move along, the hardened slime softens and its adhesive properties are reversed.
While we’ve had non-marking, removable adhesives for a while, a removable, strong and – most importantly – truly reusable adhesive has yet to hit the market. Of course there’s the ingenious Geckskin but that’s more of a mechanical adhesive, using a process known as “draping adhesion” (akin to those gooey Wacky WallWalker toys from the ’80s).
The problem to date has been two-fold: Removable, reusable adhesives are handy, but not very strong (and not as reusable as we’d like), while strong adhesives like super-glue are completely irreversible. What we really need is the best of both worlds.
So, with this challenge in mind, the research team tore a slimy page out of the snails’ book of reversible, super-adhesion and set to work. Led by Shu Yang (a professor in both the Department of Materials Science and Engineering and the Department of Chemical and Biomolecular Engineering), the team made the discovery almost by accident. While working on another project using a hydrogel made of a polymer called polyhydroxyethylmethacrylate (pHEMA) – commonly used in contact-lenses – researchers noticed that it had remarkably similar adhesive properties to that of the snail’s epiphragm.
In short, pHEMA was rubbery when wet, but rigid when dry. In fact, when it was dry, it became as stiff as a plastic bottle cap. But pHEMA had another trick up its slimy sleeve. Unlike most glue-like substances, when pHEMA dries, it doesn’t shrink and pull away from the surface, and it’s this attribute which creates its incredibly secure bond with a surface.
“When it’s conformal and rigid, it’s like super glue,” says Yang. “You can’t pull it off. But, magically, you can rewet it, and it slips off effortlessly. Additionally, pHEMA doesn’t lose its strong adhesion when scaled up. Usually, there’s a negative correlation between adhesion strength and size. Since pHEMA is not dependent on a fragile structure, it doesn’t have that problem.”
To prove this scalability point, Jason Christopher Jolly (co-first author on the paper) volunteered to climb into a harness held up by a postage-stamp-sized patch of the pHEMA-based adhesive, and survived to tell the tale. This and other tests in the lab showed that while pHEMA might not be up among the strongest adhesives out there, it’s certainly the strongest among reversible adhesives to date.
So, where next? The applications for a strong, yet reversible adhesive are endless. From non-destructive yet strong household tasks, to assembly lines and even making glued products easier to pull-apart and repair.
“Car assembly uses adhesives, and, you can imagine, if there are any mistakes putting parts together, the adhesive is set and the parts are ruined,” says Yang. “A car is pretty big. Usually they don’t glue things together until the last step, and you need a room-sized oven to host the car and cure the adhesives. An adhesive that’s strong and reversible like pHEMA could completely change the process of car assembly and save money because mistakes wouldn’t be so costly.”
But while pHEMA is truly impressive, the research team acknowledges that since its reversibility is influenced by water, it’s not quite suitable for widespread applications. With this in mind, the team is keen to move forward with further investigation into finding – or engineering – similar adhesive polymers.
Getting a filling isn’t always the end of a tooth’s cavity problems. Sometimes, bacteria is able to get down between the filling and the surface of the tooth, causing another cavity to occur. A new antibacterial dental restorative material, however, could help keep that from happening.
It should be noted that this isn’t the first bacteria-killing filling material we’ve seen. Most of the others, however, work by slowly releasing antibacterial compounds into the mouth – these chemicals can be toxic to the adjacent tissue, plus they may contribute to antibacterial resistance. Additionally, the fillings will presumably start running out of the compounds at some point.
With these limitations in mind, a team from Israel’s Tel Aviv University started with a dental resin composite, then added a modified amino acid known as fmoc-pentafluoro-L-phenylalanine. The latter remains within the resin, and has a nanostructure that ruptures the outer membranes of cavity-causing bacteria as they come into contact with it – thus killing them.
Additionally, the antibacterial resin is “aesthetically-pleasing” in appearance (unlike the old-school mercury fillings), plus it’s mechanically rigid. By contrast, the mechanical strength of some previously-developed antibacterial restorative materials was compromised by the presence of the compounds within them.
“The minimal nature of the antibacterial building block, along with its high purity, low cost, ease of embedment within resin-based materials and biocompatibility, allows for the easy scale-up of this approach toward the development of clinically available enhanced antibacterial resin composite restoratives,” says co-lead scientist Dr. Lihi Adler-Abramovich.
A paper on the research, which was also led by doctoral student Lee Schnaider, was recently published in the journal ACS Applied Materials & Interfaces.
Let’s face it: due to the amount of thrust required to lift a person off the ground, practical personal jetpacks may never exist – at least, not for use in the air. Underwater jetpacks, however, are another story. We’ve seen a fewlately, with one of the latest incorporating a novel backpack unit.
Created by Hong Kong-based AquaBeyond, the SubCruiser is intended to propel users through the underwater world, augmenting but not necessarily replacing their swim-kicks.
It consists of three main parts, all of which are hard-wired together. There’s the backpack, which contains the two battery packs and the “brains,” there are dual thrusters that can either be strapped to the thighs or mounted onthe backpack, and there’s a controller that gets strapped to one wrist.
Using a thumb wheel on that controller, users select their speed. At maximum output, a combined 10 kg (22 lb) of thrust takes them up to a claimed 4 knots (5 mph or 7 km/h). It should be noted that the controller is stepless, meaning it that smoothly ramps the speed up and down – some other similar devices can only be abruptly switched between Fast and Slow presets.
The SubCruiser is submersible to a maximum depth of 300 meters (984 ft), with one charge of its 22-volt/4.5-Ah lithium batteries reportedly good for 40 minutes of maximum-output use. And despite that depth rating, it looks like it’s mainly intended for use by snorkelers. There are shots of it being utilized by scuba divers, with the backpack being worn on front (over top of their buoyancy control devices), but that looks like it could be a little unsafe.
Should you be interested, the SubCruiser is currently the subject of a Kickstarter campaign. A pledge of US$299 will get you a system, when and if it reaches production. The planned retail price is $600.
How safe would you feel, going back into a multi-story building that had just been through an earthquake? A new sensor system could allay your fears, as it optically measures how much a building has swayed, and thus how damaged it may be.
Some buildings already incorporate accelerometers on multiple floors, which are used to determine the extent to which those floors move from side-to-side. According to scientists at California’s Lawrence Berkeley National Laboratory, though, such systems can be costly, plus processing the data from them can be a complex and time-consuming process.
With that in mind, the Berkeley Lab researchers teamed up with colleagues from Lawrence Livermore National Laboratory and the University of Nevada-Reno, creating what is known as the Discrete Diode Position Sensor (DDPS).
In development for the past four years, it consists of a laser mounted on one floor, that shines a beam down onto a rectangular array of light-sensitive photodiodes on the floor below. As the building sways in an earthquake, the laser beam moves back and forth across the array, providing an electronic record of how much the two floors have moved laterally relative to one another.
Once the earthquake is over, centrally-located authorities can consult that wirelessly-transmitted record in order to instantly determine if the building exceeded its maximum structural tolerance. If it didn’t, then it can be safely reoccupied.
The DDPS has already been shown to provide accurate readings when subjected to shake table testing, and is now about to be installed in an actual multi-story building – on the Berkeley Lab campus – for the first time. Because the campus is situated adjacent to the highly-active Hayward Fault, the system should see a lot of action.
“Until now, there’s been no way to accurately and directly measure drift between building stories, which is a key parameter for assessing earthquake demand in a building,” says Berkeley geoscientist David McCallen, who is leading the research project. “We are excited that this sensor technology is now ready for field trials, at a time when post-earthquake response strategies have evolved to prioritize safe, continued building functionality and re-occupancy in addition to ‘life safety’.”
If you think vinegar is just for pickling vegetables or for making homemade dressings, then prepare to be amazed by all the surprisingly wonderful things vinegar can do around the house. Aside from fermenting kombucha, preserving ketchup, and offering hot sauce and mayonnaise a sweet kick, vinegar has many uses in the home.
Whether it’s white distilled or apple cider vinegar, this miracle solution can do a lot: clean the home, rid hair of yeast overgrowth, cut through grease, remove stains. Vinegar can even breathe a second life into wilting lettuce.
Both vinegar and citrus peels contain the acidity and grease-cutting capabilities that make for an unstoppable cleaning force. Together they can dissolve soap scum and other yucky build-ups. While white vinegar is sometimes too hard for certain surfaces — like granite, marble, stone, hardwood floors, and cast iron pans — it is generally effective at cleaning windows, mirrors, glass, drains, garbage disposals, bathroom steel fixtures that suffer from mineral deposits, hard water build-up, and soap scum, laminate, ceramic tile, appliances like ovens, refrigerators, microwaves, and dishwashers, and stainless steel.
To make the all-natural cleaner, add citrus peels to jar (can be lemon or orange peels). Fill the jar to the top with white vinegar. Let the mixture sit for two weeks before straining out the peels and diluting 1:1 with water.
Liven up leafy greens
This one’s pretty cool; vinegar actually has the ability to perk up wilting leafy greens. If you have some lettuce in the fridge that seems on the verge of going bad, toss them in a mixture of cold water and white vinegar. It will liven the greens up a bit, giving them a few extra days of life. Wondering why it works? The acidity of vinegar encourages cell turnover in the limp lettuce, therefore causing an increase of water absorption. You also might want to cut off any far-gone, browned parts of the lettuce before bathing it in the water-vinegar mixture.
Vinegar cuts through grease in all-natural way that not even dish soap sometimes can. To wash dishes, you can use either white or apple cider vinegar. Both of the same grease-cutting effect.
The average American runs anywhere from four to five loads of laundry per week. Using vinegar as an all-natural fabric softener can help ease the carbon footprint of those many necessary loads of wash.
Add three to four teaspoons of vinegar to your normal dish detergent for optimal results. For glassware, use a ratio of 1 part vinegar to 3 parts water; let the glassware air dry. For particularly greasy pans, boil two to three cups vinegar in the pan; it will restore the pan’s original non-stick quality.
Vinegar acts as a double agent when it’s used in laundry; not only is it a powerful deodorizer, but it also functions as a gentle and non-toxic fabric softener. To use vinegar in your wash, pour half a cup of distilled white vinegar into the machine in place of conventional detergent. To use vinegar as a fabric softener, pour 1 cup of vinegar into the washing machine during the final rinse cycle.
Vinegar doesn’t just do wonders in the wash; it’s also beneficial for pre-treating stains. Dilute one-half cup of vinegar in a gallon of water and apply the mixture directly to the stain with a clean cloth. Then, wash.
White vinegar is exceptional at whitening and brightening your clothes, but also removing yellow underarm stains from perspiration (as well as odor), and also mildew stains. When added to baking soda to make a type of paste, vinegar can also dissolve red wine stains. It also is handy for deodorizing and removing cat or dog urine stains out of carpets and removing grass stains.
Say what?! Cats loathe the smell of vinegar, so vinegar spray can be super effective in dissuading cats from clawing or climbing on furniture. Vinegar can be especially effective for cats who “mark their territory” in territory other than a litter box. Spray the marked area with vinegar to rid the smell and prevent future accidents.
Remove water stains from wood
For those frustrating times when you or a guest forgets to use a coaster, vinegar can help. It actually rids wooden furniture of that annoying water ring. All you have to do is take a mixture of equal parts vinegar and vegetable oil and rub it on the stained surface, going with the grain.
Defrost your car in winter
The acidity of vinegar allows it to melt ice more quickly. The acetic acid in vinegar lowers the melting point, but sometimes it’s best to use vinegar as a preventative measure to defrosting car windows. Spray a mixture of apple cider vinegar and water on your car windows the night before snow or freezing temperatures are expected. The acidity prevents the ice from forming in the first place.
Use as Goo-Gone alternative
Who needs Goo-Gone when you have a gallon of household vinegar at your disposal? The acetic acid in vinegar is strong enough to cut through the sticky mess that things like bumper stickers, labels, and stickers leave behind.
Saturate a paper towel in white vinegar, then place the towel over the adhesive for up to five minutes. Pull up one corner of the sticker — no razor blade required. Instead, you could use a spatula or even a credit card to peel it back. Leftover adhesive residue? Take a clean cloth saturated in white vinegar and rub the affected area.
The US Army says that it will conduct live-fire tests of a new Robotic Combat Vehicle next year. While the tests won’t involve vehicles ultimately slated to go into combat, they will be used to show off various technologies that may later be incorporated into platforms in the future, and how soldiers might eventually utilize them on the battlefield.
The RCVs are built on an M113 armored personnel carrier, and will be controlled by soldiers in a vehicle called the Mission Enabler Technologies-Demonstrators (MET-Ds), an upgraded Bradley Fighting Vehicle. The MET-Ds will be equipped with cameras and a remote turret, which crew members will control with touchscreen panels.
The first phase of testing will begin next March at Fort Carson in Colorado, and will feature a pair of MET-D vehicles and four RCVS. Each MET-D will be controlled by a driver, a gunner, and four soldiers, who will control a pair of RCVs to assess platoon-level maneuvers. The Army’s Combat Capabilities Development Command’s Ground Vehicle Systems Center and the Next-Generation Combat Vehicle Cross-Functional Team, will then look over the results and make adjustments for future tests.
The next phases will be bigger: An infantry unit will test out the RCVs in Europe next May, and another test will take place sometime in late 2021, which will see six MET-Ds and four M113 RCVs, along with four light and medium RCVs to conduct company-level maneuvers. A third phase will take place in 2023, with six MET-Ds and four M113 RCVs, along with four medium and heavy RCVs.
Mission Enabler Technologies-Demonstrator (MET-D) vehicles: leveraging the latest tech in cameras, data display, GUI, drive-by-wire capability, unmanned aerial vehicle-provided video, & advanced comms to help w/ battlefield situational awareness & enhance communication capability pic.twitter.com/SyWTwohq5g
— U.S. Army CCDC Ground Vehicle Systems Center (@CCDC_GVSC) July 1, 2019
The Army has been working for several years to develop armored robotic vehicles, but the vehicles being used in these tests aren’t the actual robotic vehicles that will eventually end up in combat — they’re surrogate vehicles designed to simulate a future platform. These tests are aimed not at the vehicle capabilities, but at how their operators utilize them and to learn how to best use future robotic vehicles to attack an enemy without putting soldiers directly in the line of fire.
David Centeno Jr., chief of the center’s Emerging Capabilities Office, says in the release that when US forces come under fire, the Army will need to “find ways to penetrate that bubble, attrit their systems, and allow for freedom of air and ground maneuver.” These robotic systems would be able to do that: they’re mobile platforms equipped with cameras and guns, which could be directed into the line of fire by soldiers who are well out of range. The vehicles are expected to be smaller and faster than the crewed vehicles that the Army currently fields. Because they won’t actually carry people, they wouldn’t need to be as heavily armored, and could dedicate more space to weapons or fuel.
The Army is currently working to develop future RCV platforms. In May, it held a demonstration event, which saw six different teams test out eight remotely-controlled robotic vehicles on a course in Texas. The Army used the demonstration to begin figuring out what the best approaches are for building future vehicles and what role they might play on a future battlefield.
Ahead of this weekend’s Bastille Day celebration on Sunday, French President Emmanuel Macron announced the creation of a space command that would be part of the country’s Air Force, according to Reuters.
President Macron made the remarks to military personnel, saying that the space command would be responsible for defending the country’s satellites, and that it would officially be created in September. The Air Force, he says, will eventually be renamed as Space and Air Force. It appears as though this new command will replace France’s existing Joint Space Command, which is already responsible for France’s existing space assets, and coordinating with the militaries of other European nations.
While it has the third-oldest space agency, France has begun to focus more on space in recent years. According to Breaking Defense, the country plans to spend 3.6 billion euros between now and 2025, and in December 2018, it launched a new military reconnaissance satellite, the CS0-1, with more to follow in the coming years.
In recent years, a number of countries have begun to recognize space as a distinct “domain” of warfare — a distinct location or concept where warfare can take place, such as on land, sea, air, or space, or within digital systems. This command appears to be France’s answer to addressing the the problems that space-borne military infrastructure potentially brings.
France’s new command looks as though it would be analogous to the United States Space Command, a part of the US military originally founded in 1985 to oversee and coordinate the country’s orbital assets, like satellites. That command was disbanded and merged into the US Strategic Command after the September 11th attacks. Last year, President Donald Trump ordered the Department of Defense to create a new Space Command, a precursor to a new, full-fledged branch of the military, Space Force.
As the line between film and television continues to blur, big-screen movies are still supposed to flaunt their scope. In a summer where plenty of would-be blockbusters are withering at the box office, and plenty of potential moviegoers seem to be staying home to watch Stranger Things, size and scale remain selling points for the theatrical experience. Avengers: Endgame hops around planets and time-streams. Men in Black: International zips between continents like a James Bond picture. Even your friendly neighborhood Spider-Man takes a whirlwind tour of Europe.
Some of these big-scope adventures do deliver the requisite cinematic thrills. But as plenty of blockbusters deflate into disappointment, a different sort of summer movie has been making headway. In the lackluster summer of 2016, The Shallows (in which a stranded Blake Lively matches wits with a shark) and Don’t Breathe (in which trapped young people match wits with a wily, murderous blind man) provided more efficient and consistent thrills than a lot of their super-sized, mega-budgeted counterparts. Call them limited-location thrillers. So far this summer, the limited-location thriller to beat is the underhyped Crawl, in which a hurricane-stranded Kaya Scodelario matches wits with a pack of alligators.
Crawl isn’t as well-crafted as either The Shallows or Don’t Breathe, though it shares a producer with the latter: Sam Raimi, whose first two Evil Dead movies are gonzo versions of the limited-location thriller. Hit-and-miss horror auteur Alexandre Aja knows how to deliver lean, mean horror action. Crawl is far less tongue-in-cheek than his Piranha remake, but it doesn’t build to a fever pitch or deliver dynamite setpieces.
It does, however, maintain its tension in a way that outshines many of this year’s summer thrill rides. The setup is an ingenious hybrid of disaster movie and creature feature: College student Haley (Scodelario) drives to her old family home in the midst of a hurricane to make sure her dad (Barry Pepper), who hasn’t been answering his phone, is safe. She finds him gator-bitten and unconscious, and as their house floods, she realizes the alligators are pouring in along with the rainwater. Father and daughter must avoid both drowning and massive alligator teeth; much of the movie’s 87 minutes takes place in the rapidly flooding house.
That limitation is a major asset. Crawl has plenty of computer effects, but unlike so many movies whose reach exceeds their effects budget (especially in disaster-movie circumstances that seemingly call for large-scale destruction), it doesn’t require its characters to spend the entire movie in front of obvious green screens in a desperate simulation of epic scope. The weather effects are obviously computerized, but the house itself is a real set, flooded with at least some real water. When Haley first ventures into the basement to find her dad, Aja plays up the muck, gunk, and early hints of gore for all they’re worth. Because the set dressing feels so tactile, the movie creates a genuine sense of atmosphere in a potentially generic setting.
Content to explore its small-scale setting, the movie never drifts off into location-hopping weightlessness as Haley swims, jumps, and, yes, crawls around various tight passages and makeshift waterways. When the alligator bites come, they feel especially toothsome thanks to practical gore effects, and the stuntwork creates a more believable athleticism for its character—much moreso than stars who must be replaced by a CGI wire-frame cartoon every time they do something superheroic. If Crawl doesn’t have a standout setpiece, it’s because the whole thing moves so quickly and efficiently.
This includes the obligatory emotional backstory, which is basically a feature-length version of the “gymnastics” foreshadowing involving Malcolm’s daughter in The Lost World. Haley is a competitive swimmer. (Guess what stroke she specializes in?) Her dad is her former coach who may have pushed her too hard. Of course a bizarrely coordinated alligator attack turns into a proving ground for her swim skills, and maybe even a catalyst for family healing. This is all about as corny as it sounds, but like The Shallows, Crawl treats its lead character’s boilerplate with dignity, anchored by Scodelario’s no-fuss lead performance. It’s silly, sure, but it also has a pleasing clarity — nothing in this movie feels like it was frantically and haphazardly rewritten in the editing room. Alligators chase a resourceful swimmer; what’s to rewrite?
Yet even the studios that make movies like Crawl don’t always seem to understand the relative blessings they have on their hands. In spite of Aja’s decent track record, his movie wasn’t widely screened for press. This seems especially strange in a week where extremely mixed reviews for the would-be spectacle and scope of The Lion King popped all across the internet. This summer in particular, no studio should be ashamed to release an unpretentious, well-paced bit of entertainment like Crawl — and audiences shouldn’t feel ashamed to leave the comfort of their homes to check it out.
Megvii, a Chinese AI startup that supplies facial recognition software for the Chinese government’s surveillance program, is expanding its technology beyond humans to recognize different faces of pets. As reported by Abacus News, Megvii’s new program is trained to recognize dogs by their nose prints — much like how humans have unique fingerprints.
Using the Megvii app, the company says it can register your dog simply by scanning the snout through your phone’s camera. Just like how a phone registers your fingerprint for biometric unlocks, the app asks you to take photos of your dog’s nose from multiple angles. Megvii says it has an accuracy rate of 95 percent and has reunited 15,000 pets with their owners through the app.
Facial recognition for pets is becoming more widespread over the past few years. The concept has been used by researchers for wildlife conservation. Over in the US, an app called Finding Rover also uses facial recognition technology to locate cats and dogs that are reported as missing.
But in China, Megvii says its app will be used for more than just reuniting owners with their lost pets. With its existing relationship with the government, it says its app can also be used to monitor “uncivilized dog keeping” to fine civilians who don’t pick up after their dogs or allow them to walk without leases in public spaces.
Following the 2016 presidential election, states like Pennsylvania indicated that they would be working to upgrade their voting machines to allay security concerns. A new report from the Associate Press reveals that while counties across the United States have purchased new equipment, many of machines are running outdated software that could still be vulnerable to hackers.
At the heart of the issue is the operating system that the machines run on — Windows 7. Microsoft released the operating system between 2009 and 2014, and it’s since been overtaken by Windows 10. The company has scaled back its support for the OS, and will officially end support for it next January.
In an analysis of voting machines across all 50 states, the AP says that it “found multiple battleground states affected by the end of Windows 7 support, including Pennsylvania, Wisconsin, Florida, Iowa, Indiana, Arizona and North Carolina.” Some states, like Georgia and Michigan, are considering new systems that use Windows 7.
Furthermore, the AP says that two of the three major election equipment vendors — Election Systems and Software LLC, and Hart InterCivic Inc — supply machines running outdated software: Hart InterCivic’s operating system will reach the end of its mainstream support on October 13th, 2020 (apparently Windows 10 Enterprise 2015 LTSBWindows 10 IoT Enterprise 2015 LTSB), while Election Systems and Software says that it will be offering a new system running on Windows 10. However, it’s unclear if that will be cleared for use and distributed to counties before the 2020 election in November. The AP says that a third vendor, Dominion Voting Systems Inc., is unaffected by the issue, but points out that it does have systems that it “acquired from no-longer-existing companies that may run on even older operating systems.”
As states begin to prepare for the 2020 elections and place orders for new systems, state officials in Pennsylvania, Michigan, and Arizona have indicated that they have spoken with vendors about the software on the machines.
Election vendors also have had notable problems with security — Election Systems and Software disclosed that it installed potentially-vulnerable remote access software on its machines, while Russians breached the computer systems of another vendor, VR Systems, and were able to break into the voting databases of two Florida counties prior to the 2016 election. To be clear, individual machines are notoriously vulnerable to hackers, but the decentralized nature of the US’s election infrastructure means that it’s hard to change votes en-masse. But, with a close election, foreign agents could potentially mess with election results, or at the very least, undermine confidence in the final results.
Microsoft tells the AP that it will issue free security updates for Windows 7 through 2023. But, while the company can continue to release patches for its systems, system owners will need to actually install them. In 2017, the WannaCry cyberattack crippled thousands of computers in over 100 countries that were running versions of Windows XP and Windows 7 that didn’t have security patches installed. Windows ended up issuing a special patch for Windows XP users, and has since released additional patches to fix new vulnerabilities. But even more than two years later, Microsoft says that more than a million computers are still vulnerable to security exploits.