Nano 'Yarn' to Power Biomedical Implants
Wool yarn doesn't power implants, but one made of carbon nanotubes was used to build a microscopic structure for a tiny biofuel cell.
Sept. 27, 2011 --
In the popular "Deus Ex" video game series, nanotechnology can turn an average government agent into a bionic superman. In fact, nanotech augmentations in the human body aren't just fun and games. Real-life applications will most likely become reality a lot sooner than you think. In 2007, the world's first online inventory of nanotech products, Project on Emerging Nanotechnologies, found that nearly 500 products, including food, clothing and cosmetics, employed nanotechnology. In this slide show, explore how nanotech can make you stronger, tap into your brain and more.
WATCH: NANOTECH REWARDS
If you're too busy to make it to the gym, nanotechnology could be a way to get fit without having to spend hours toiling away on machines. In fact, technology can take you a lot further than any free-weight or cardio regimen. In 2006, researchers at the University of Texas at Dallas reported in the journal Science that they had created alcohol- and hydrogen-fueled artificial muscles 100 times stronger and capable of 100 times more work than natural muscles. Functioning as both muscles and fuel cells, the technology has a range of applications from artificial limbs to autonomous robots.
SCIENCE CHANNEL: Take the Nanotechnology Quiz
If nanotechnology can make you stronger, could it also make you smarter? Scientists aren't quite there yet, but nanotechnology applied to brain implants could treat a range of conditions from deafness to blindness to Parkinson's disease and more, according to biomedical engineers from the University of Michigan. Nanotechnology could also be used to tap into the mind, and read and write information directly into the brain. In an unusual twist, the research was undertaken by telecommunications engineers at Nippon Telegraph and Telephone.
University of Washington
Contact lenses with visual displays may seem like the kind of technology you only see in a movie. But researchers at the University of Washington have started laying the groundwork by building a contact lens with internal circuitry. Using wires made of metal only a few nanometers thick, the technology is placed in a contact lens rather than an implant, making use of the bionic eye much easier. In this photo, the contact lens has been affixed to a rabbit. The researchers believe they would quickly be able to introduce a visual display, but it wouldn't be more than a few pixels in the near future.
Tired of having to find an electrical outlet or a USB cable every time you need to charge your cell phone? With nanotechnology, you can become a walking battery. Using nanowires to recover wasted heat energy from the body, which is then converted into electrical power, researchers with the U.S. Department of Energy’s Lawrence Berkeley National Laboratory and the University of California at Berkeley have developed an entirely means of charging personal electronics. The same technology could be used to convert heat from other sources into electrical energy. As reported in the journal Nature, approximately 15 trillion watts of heat energy produced by engine and steam- and gas-powered turbines is lost to the environment.
Recovering from injuries to skin and muscle tissue can take weeks. Trauma to the brain or central nervous system can be irreversible. But with nanomedicine, a nanoparticle-infused hydrogel could heal brain and bone injuries by creating new blood vessels and encouraging stem cells to replace dead tissue. Developed by scientists from Clemson University, the gel still needs several more years of animal testing before human trials can begin. Injuries involving nerve damage or the spinal cord are among the most difficult to treat. But nanotechnology could open the door to rebuilding damaged nerve cells. Although regenerating nerve cells is the ultimate goal, researchers have so far been able to develop the scaffolding necessary to rebuild nerves following damage. The technique, a nanotechnology-infused stem cell treatment developed by David Nisbet of Monash University, could also aid in the treatment of Parkinson's disease.
Besides treating immediate injury, researchers are also exploring uses of nanotechnology to fight the effects of aging and to promote longer life. By using a breakthrough nanogel to stimulate stem cells, Northwestern University scientists found that they can regenerate lost cartilage in joints. As adults age, they start to lose their cartilege, a painful condition for which there is little effective treatment. A separate study undertaken by researchers at the University of Central Florida (UCF) found that using an industrial nanomaterial, they can triple or even quadruple the lives of brain cells. This could lead people "live longer and with fewer age-related health problems," according to a UCF press release about the study.
With more than an estimated 1.5 million new cancer patients this year alone, it's no surprise that one of the more promising applications of nanotechnology is in the detection, monitoring and treatment of various forms of cancer. From targeted drug delivery to direct attacks of "nanoworms" on tumor growths, researchers working within the field of nanomedicine are using the technology to attack cancer cells with unprecedented precision.
WATCH: NANOTECH RISKS
Imagine a pacemaker or bionic ear that doesn't require batteries but is powered by your very own cells.
That could be the future of biomedical implants once biofuel cells come to fruition, says an international team of scientists, who have taken the technology one step closer to reality.
The researchers have created a biofuel cell made from carbon nanotubes that generate energy from blood glucose.
The advance improves the power output and the lifetime of biofuel cells, they report in the journal Nature Communications.
Unlike batteries, which store chemical energy, conventional fuel cells convert a fuel such as hydrogen or methanol into electricity.
Biofuel cells, which have been in development since the 1960s, employ the same principle except they use biological enzymes to convert glucose into electricity inside the body.
However, there have been a number of serious technical hurdles that have impaired their performance, says study co-author Professor Gordon Wallace from the University of Wollongong.
One of the challenges is "immobilizing" the enzyme that converts the fuel into electricity and making it stick to the electrodes of the fuel cell, rather than diffusing through the cell and into the fuel.
Another challenge is keeping the immobilized enzyme active for long periods of time.
"This is because the electrodes, like anything implanted in the body, tend to get fouled and performance drops off quite quickly with time," says Wallace.
This has resulted in low power densities of only a few milliwatts per centimeter squared and a lifetime of only a few days, which is insufficient for practical use.
To tackle these problems Wallace and his colleagues turned to carbon nanotubes, which are microscopic cylinders made from long strings of interconnected carbon atoms.
Wool yarn doesn't power implants, but one made of carbon nanotubes was used to build a microscopic structure for a tiny biofuel cell.Thinkstock
They used a form of multi-walled carbon nanotube "yarn" to construct a microscopic structure for the biofuel cell.
"This provides an environment that gives stability to the enzymes and an environment that occludes the types of things that can poison the enzyme, therefore degrading its performance over time," says Wallace.
The end result was a biofuel cell with an extended lifetime and a higher power density 2.2 milliwatts per square centimeter.
"In terms of the power density it's a factor of two or three above what we were getting. That's probably not staggering, but it is significant," says Wallace.
"What is more significant is the length of time we can operate these biofuel cells for."
The researchers are aiming to develop the carbon nanotube yarn biofuel cells to power an implant that will help regenerate nerve damage.
"Our initial target is for peripheral nerve repair, whether that's a finger or other limbs."
The idea is to implant the conduit in the area where the nerves need to be regenerated, and the biofuel cells will produce a tiny electric current to stimulate nerve growth without requiring batteries or an external power source.
Wallace and his collaborators are also working on improving the power output and lifetime of biofuel cells even further.
"That then opens them up to powering all sorts of implants, not just this temporary power supply to repair a damaged area, but a power supply that will be able to service in an ongoing prosthetic, like the vagus nerve stimulators for epilepsy or for chronic pain management."
The ultimate goal is to boost output and longevity to the point that biofuel cells can power a broad range of biomedical implants.
"If you can think of any type of device that is implantable that requires energy, this would be a great way to power it so you don't have to go in and change the batteries all the time," says Wallace.