A piezoelectric device powered by viruses. Photo courtesy of the Lawrence Berkeley National Laboratory.
Piezoelectric power harvesting has drawn much attention, given its ability to generate electrical energy from mechanical energy. One example includes experimental floor pad installations created to translate the energy produced by foot traffic through subway turnstiles into usable power. Piezoelectricity, which was first discovered in the late 19th century, has three major drawbacks, though: it typically involves materials that are highly toxic and unmanageable, it doesn't produce much power, and it is rather delicate in nature.
Recent experiments conducted at the Lawrence Berkeley National Laboratory (LBNL) have the potential to improve upon the first two challenges, however. Rather than use traditional chemicals, the LBNL scientists turned to living matter for solutions to the problems of toxicity and inefficiency. A research team led by Seung-Wuk Lee, a professor in LBNL's Physical Biosciences Division, has developed piezoelectric technology based on engineered viruses. The primary mechanism is the harmless M13 bacteriophage virus, a specimen coated with 2700 charged proteins that allow the organism to convert mechanical into electrical energy as a piezoelectric nanofiber. The virus also exhibits the trait of self-assembly, thus greatly reducing the required effort to manufacture coatings comprised of the biologial material.
To test the virus-driven piezoelectrics' efficiency, the research team created a demonstration prototype device using one square centimeter of virus-coated film connected to an LCD display. Pressure delivered by touch produces approximately six nanoamperes of current—or 25 percent of the voltage of a AAA battery—which is enough to illuminate the display.
“More research is needed, but our work is a promising first step toward the development of personal power generators, actuators for use in nano-devices, and other devices based on viral electronics,” Lee said. “Because the tools of biotechnology enable large-scale production of genetically modified viruses, piezoelectric materials based on viruses could offer a simple route to novel microelectronics in the future.”
