Dec 9 2007
Biomedical and microelectronic devices could be better protected thanks to research underway at Rutgers University - Camden that aims to improve the coating of polymers in smoothness and uniformity, no matter how intricate the product.
Daniel Bubb, an associate professor of physics at Rutgers-Camden, has identified the conditions that ensure thorough polymer coating through a matrix-assisted laser process. Polymers are materials made from long chains of molecules and are used in a variety of industries often as a protective coating from contact lenses to battleships.
A $298,785, three-year National Science Foundation (NSF) grant is allowing Bubb and his team (including a post-doctoral fellow and undergraduate biology students) to continue pinpointing what solvents best interact with polymers for precise coating, and compiling new data on the effects of wavelengths on specific properties.
Bubb and his team employ a patented pulsed laser deposition technique, where a high-power infrared laser is focused onto a target material in a vacuum chamber, creating a plume of vaporized material. The object that is to be coated is placed in the path of the vapor and the laser is then tuned to a specific vibrational mode of the polymer. The Rutgers-Camden physics team has improved this process by tailoring specially blended solvents to particular polymers prior to the vaporization process and implementing an infrared laser on tested wavelengths that either completely remove or significantly limit any photochemical or photothermal damage.
“Our work emphasizes the role of the polymer solvent interactions. If we start to precipitate the polymer with the solvent and it gets cloudy, it means the polymer isn’t well separated. That means clusters would appear in the coating as unfavorable bumps,” says the Rutgers-Camden researcher. In industry, these unfavorable bumps could result in damage to the device being coated, be it a hearing aid or semiconductor.
Bubb’s research has far-ranging applications, including providing sterile coatings for intricate biomedical devices, like pacemakers or artificial joint replacements, and making multilayered structures, like television, cell phone, or laptop displays lighter and less reliant on voltage.
“The primary advantage of organic electronics, like polymer LEDs used in a variety of displays, is the lower power consumption and reduced environmental impact. Lower power consumption means the devices can be more compact and portable. It’s pretty clear with the advent of the iPhone that consumers want lots of features and capabilities in a small footprint,” remarks Bubb. In addition to being less transportable, computers made from conventional semiconductor electronics contain harsh metals, like lead or mercury, and are difficult to recycle.
“The reduced power consumption will have a positive impact on our use of energy resources – both renewable and nonrenewable,” Bubb adds.