Archive for the ‘Polymers’ Category

The Future of Polymer Solar Cells

Sunday, September 18th, 2011

One of these days our fossil fuel reserves will expire. That is a given. As of today alternative green sources of energy are being researched and experimented with. As long as I have been alive people have been talking about solar panels as a means to power our energy grid. Unfortunately, silicon solar panels are expensive, difficult to adhere to surfaces, delicate, and simply do not capture enough energy from the Sun to be viable. All of these problems make silicon yesterday’s news, it’s time for polymer solar cells to hog the spotlight.

Admittedly today’s polymer solar cells do not retain as much energy as rigid silicon cells. This issue is worked on every day, but that is where the downsides of polymer solar cells end. Polymer solar cells are incredibly lightweight, they can be customized on a molecular level, they have a lower environmental impact, and most importantly they are incredibly flexible; thus making them easy to adhere to surfaces that could not stand the weight of silicon cells.

While a breakthrough in capturing a larger quantity of solar energy is still needed from the polymer solar market, small advancements in other areas of their development have been happening frequently. Recently UK scientists from the Universities of Cambridge and Sheffield have developed a polymer solar film that can be applied to surfaces with ease. They describe the material as a “cling film”, basically a Saran™ wrap that can capture solar power. This cheap, pliable material could be installed onto many things requiring electrical power. Imagine being able to coat your home in this material, soaking up the midday sun could drastically cut down on your energy costs.

Another small victory for the polymer solar market is the advent of thin-film solar. These very small, lightweight solar cells also boast the ability of adhering to surfaces that silicon cannot be applied to. They can stick to handheld devices, oddly shaped objects, and clothing. Recently Mekoprint, a Danish company, has developed a small handheld, solar charged flashlight. It operates by absorbing light during the day, storing that power in a lithium-ion battery, and using a LED as its light source.

One of the most interesting current research projects comes from a solar company in Lowell Massachusetts. Kornarka Technologies is working on a polymer cell that can absorb infrared light. The obvious advantage of this cell is that it can absorb energy all day and night; not being relegate to only daytime use would allow solar cells a large increase in efficiency.

This article is not meant to convince you that polymer solar cells will solve all of our problems tomorrow. Simply put, solar energy in total is just not there yet. Many more research hours and dollars will need to be spent before we can say good-bye to fossil fuels. It is clear however that plastic is making the future look a lot brighter.

MIT Produces Vocal Cord Repairing Polymers

Sunday, July 24th, 2011

It never fails to astonish me. The minds fostered at MIT always seem to come up with truly incredible things. They have given us Ethernet, perfected radar and even invented those nifty little disposable razors that I couldn’t possibly live without. This summer they are working on giving people with damaged vocal chords back their lost voices. Are they growing new vocal cords in a lab? Are they getting organ donations? Are they giving volunteers small computers that can vocalize for them? Of course not! Obviously they’re using polymers!

This magical polymer is known as PEG30, which is a modified polyethylene glycol. It actually mimics the elastic properties of vocal chords. The technical term for the pliability of the vocal cords is viscoelasticity. PEG30 is flexible, durable and responds effortlessly to the movement of air. Simply put, normal lung power causes PEG30 to form the shapes needed for proper speech to be achieved.

PEG30 will mostly be used in individuals who have vocal cord scarring. This ailment is more common than you think. Vocal scarring generally occurs in children who have been intubated. In an emergency situation, where a child needs oxygen quickly, gentle treatment of the vocal cords is not at utmost priority. The British Singer/Actress Julie Andrews is likely the most famous example that comes to mind. In 1997 she underwent surgery to remove non-cancerous lesions from her throat. The subsequent vocal cord scarring that she suffered has never healed to this day, and has left her unable to sing.

Ms. Andrews plays a role in the current research being done into PEG30. Andrews approached the professor of laryngeal surgery, Steven Zeitals of Harvard University, concerning her dilemma. He had been developing a material that could be injected into scarred vocal tissue to lessen rigidity. When his research hit a wall he sought help from Robert Langer, a professor of chemical engineering for MIT. Together, they and their team have produced this wonderfully responsive vocal gel.

PEG30 is not yet in use today. It has however been found safe by the FDA. The hope is to use PEG30 in some injectable capacity. Human trials will begin in 2012, with a goal of having 10 test subjects. If PEG30 is found to be acceptable for mainstream use, %6 of the US population will have the ability and a reason to sing. I’m sure they won’t sing as well as Julie Andrews, but at least plastic helped to bring forth from them, the sound of music.

Plastic On the Frontlines of Anti-Counterfeiting

Sunday, July 24th, 2011

Since the death of barter and the birth of monetarism, a war has raged; a war between those who would earn (or steal) legitimate legal tender, and those who would counterfeit. This issue has gone on since before Cleopatra stamped her face onto bronze coins and continues on to current day. With no end in sight, what will save us from these thieves, pretenders and usurpers? Why, polymers of course!

The forefathers of plastic currency find their roots in the land down under. The University of Melbourne first developed notes composed of polymers in 1988 and the Reserve Bank of Australia were first to adopt them. These notes are made of biaxially-oriented polypropylene (BOPP) and are currently used in 32 countries around the world today. Australia took on the task to create these difficult to counterfeit bills, when in 1967 they noticed a spike in fake notes in circulation, with the advent of the color copier they feared this problem would increase drastically.

The practice of creating legal tender out of plastic heralds many advantages over paper threaded currency. For one, it is far more durable than paper; not having to replace destroyed currency has its obvious benefits. The notes are water proof; freeze proof and easily recycled into other useful items once they do finally wear out. This longer life cycle also reduces the environmental strain of manufacturing new bills. Besides durability and recyclability, plastic cash boasts security against counterfeiting which paper can never pretend to achieve.

The newest participant in the production of plastic notes is The Bank of Canada. In late June they unveiled their new $100 and $50 polymer notes. These notes will be in full circulation by March 2012, and they plan to create $20, $10 and $5 polymer notes by the end of 2013. Why the sudden switch to a completely plastic note system?

Much like the challenges Australia faced in 1967; Canada, starting in the early 2000’s has seen a dramatic spike in the circulation of counterfeit bills. In 2004 The Bank of Canada found that out of every one million paper notes in circulation, 470 of them were fakes. It may seem to be a small fraction of bogus notes to you or me, but it’s serious enough to raise alarm and devalue a currency. Whatever was The Bank of Canada to do?

When all hope was thought to be lost, a hero emerged from a newly upgraded mint, deep from within the reaches of The Bank of Canada. Equipped with the powers of raised lettering, embedded barcodes, large transparent windows with a portrait of the Tower of Peace etched upon it and an image of Prime Minister Robert Borden; the ability to change color when tilted at different angles and the most sophisticated holograph ever created. This hero came to save the Canadian monetary system and discourage and destroy the counterfeiters. This hero’s name is plastic, and plastic is so valuable that it can print its own money.