Welcome to the November installment of the Tech Buzz. This month, there’s been a LOT of buzz not only in the operating room, but also around cool new materials being built into hot electric cars and from parking lot asphalt. Fasten your seat belts, there’s some amazing stuff just down the road ahead.
Electric Wound Dressing Prevents Infections
When bacteria enters major skin wounds, especially burns, they set up biofilms that help sustain them. Bacteria biofilms not only present the risk of infection, but if they are resistant to antibiotics, can also seriously complicate patient treatment.
Though it’s been known since 1992 that weak electric fields can disrupt bacterial biofilms, no one has come up with an easy, inexpensive way to use the phenomena as a treatment. But researchers at The Ohio State University Wexner Medical Center recently figured out how to do that.
Researchers experimenting on pigs discovered that by placing a pad printed with silver and zinc directly onto a wound, that they can generate a biofilm-killing weak electric field without using wires. When moistened, the wireless electroceutical dressing (WED) generates a weak electric field that disrupts the ability for bacteria to adhere to surfaces, such as exposed wound tissue. This prevents them from creating biofilms or doing much else.
In the presence of an electrolyte, zinc and silver form a silver-oxide battery. Similar to the classic lemon battery experiment, the movement of ions from the silver and zinc creates the electric field. Zinc and silver are largely hypoallergenic metals and this makes them ideal for use in WEDs. WEDs can also be changed just like a regular wound dressing. And because the WEDs only effect bacteria but not healing tissue, they can help reduce the amount of time to heal.
Researchers will next be joining with the Department of Defense for a clinical trial to treat burn wounds in humans.
EVs Focus On Supercapacitors, Self-Healing
Forty years ago, researchers working on developing a polymer for extended wear contact lenses discovered that some of the materials they were working on were capable of conducting ions. In other words, it allowed a charged atom or molecule to pass through it. Fast forward to today and Augmented Optics Director of Research, Dr Donald Highgate, who developed that material, has teamed up with the University of Surrey in England to create a new polymer that can boost the performance of supercapacitors.
What’s a supercapacitor?
In an electronic circuit, a capacitor functions like a battery to store electricity, but to do so, it must remain plugged into the circuit. Electrolytic capacitors are a sandwich with the charge holding dielectric material in the center and the positive and negative electrodes on either side.
Supercapacitors are able to hold more electricity per mass than electrolytic capacitors as well as charge and discharge faster than batteries for thousands of times longer. But, they tend to have much lower energy densities than batteries. Current supercapacitors have an energy density of about 5 watt-hours a kilogram, compared with the 100 watt-hours of lithium ion batteries commonly used in electric vehicles. But even though batteries now supply power to EVs, it’s thought that soon supercapacitors will take their place because they are cheaper, lighter, and becoming more powerful— perhaps holding up to 10,000 times the current energy density.
The polymer being developed into a supercapacitor at the University of Surrey would cut an EV’s charge time to just seconds but allow a driver to travel over 400 miles on that single charge.
In fact, Lamborghini and MIT are already working on what might be the hottest Italian sports car ever. Earlier this month, the Terzo Millennio concept car was unveiled at the EmTech Conference in Cambridge, MA, boasting super-powered electric motors for EACH wheel. A team from MIT will be responsible for developing a graphene-enhanced supercapacitor system that will let the car fully charge in minutes. The body will be made using Lamborghini’s Forged Composite technology; shredded carbon fiber threads and resin are squeezed between a pair of steel molds then squeezed at 1,200-1,500 psi for three minutes. Plans include adding graphene technology to make the body panels work to accumulate and store electricity. But to keep the energy accumulation working, the body panels will be able to monitor and self-heal using micro-channels that generate heat to seal cracks to the carbon fiber panels.
Parking Lot Power Heats Up
With the exception of crossing the Sahara Desert or Death Valley, there’s nothing more desolate than a Texas parking lot in August.
Unless you’ve recently received a $298,000 grant to try to put some of that desolate asphalt expanse to work. University of Texas at San Antonio professor Samer Dessouky and his team are developing a technology that will enable them to convert the sun’s heat absorbed by freeways, airport runways, and parking lots into valuable sources for renewable energy.
A thermoelectric generator (TEG) generates an electric current directly by converting the difference between a cold side and hot side into electrical energy. A thermoelectric module consists of a positively charged semiconductor on one side and a negative semiconductor on the other. An electric current flows when there is a thermal difference between two sides. TEGS are used in all sorts of situations where there is plenty of waste heat, such as on vehicles or in steam generating plants.
Though larger paved areas stand best the chance to generate the most electricity, heating can be uneven. Dessouky’s team will be concentrating on those areas that store the most heat. The plan is to embed the TEGs to use the temperature differential between the pavement surface and the temperature in the soil at the pavement shoulder. It’s estimated that a single 64 × 64 mm TEG can generate .01 watt continuously over an 8 hour period. It’s likely that clusters of multiple TEGs can put out higher voltages for an equally sustained period.