Lab builds spinach-powered solar cell

Oct. 21, 2004
Researchers at Massachusetts Institute of Technology have incorporated plant life's ability to convert sunlight to energy in a solid-state device.

Researchers at the Center for Biomedical Engineering at MIT hold a spinach solution that makes up the active ingredient in a biologic solar cell.
Photo:Donna Coveney/ MIT

The device is based on a protein complex, dubbed Photosystem I, which is derived from spinach cells. The challenge was to keep the complex functioning without water or salt, two necessities for plant life. The answer was found in a peptide, or protein fragment, that acts like a surfactant in detergents. It keeps the complex working despite being deposited on cold, hard surfaces of silicon-based ICy. The peptide also stabilizes the complex and helps it self-assemble while the circuit is being fabricated.

The lab-based device consists of a transparent layer of glass coated with a conductive material and a thin layer of gold over it to facilitate the chemical reactions that self-assemble Photosystem I. Next comes the complex itself covered with a soft organic layer that prevents electrical shorts and protects the complex from the final metallic layer. Researchers shone a laser into the device, then measured the resulting current. 'We got very little current out, mostly because we had just a thin layer of the complex," says Marc Baldy, an assistant professor at MIT. "Most optical excitation passed straight through without being absorbed. Of the light that was absorbed, we estimate 12% was converted to charge."

The team hopes to create similar devices with power conversion efficiencies of about 20% by creating several layers of Photosystem I or increasing the surface area by adding three-dimensional features. The work is supported by MIT., the University of Tennessee, the U.S. Naval Research Lab, Darpa, National Science Foundation, and the Air Force Office of Scientific Research.

COMPANY NEWS

Italian aircraft builder Aermacchi has chosen SAMCEF advanced analysis software tools from Samtech s.a. to model and analyze the M346 stick/pedals mechanical links.

Agilent Technologies Inc. recently received a patent for a method that uses the Universal Serial Bus (USB) to communicate with a message-processing device and also includes some aspects of GPIB emulation.

 

Sponsored Recommendations

Pumps Push the Boundaries of Low Temperature Technology

June 14, 2024
As an integral part of cryotechnology, KNF pumps facilitate scientific advances in cryostats, allowing them to push temperature boundaries and approach absolute zero.

The entire spectrum of drive technology

June 5, 2024
Read exciting stories about all aspects of maxon drive technology in our magazine.

MONITORING RELAYS — TYPES AND APPLICATIONS

May 15, 2024
Production equipment is expensive and needs to be protected against input abnormalities such as voltage, current, frequency, and phase to stay online and in operation for the ...

Solenoid Valve Mechanics: Understanding Force Balance Equations

May 13, 2024
When evaluating a solenoid valve for a particular application, it is important to ensure that the valve can both remain in state and transition between its de-energized and fully...

Voice your opinion!

To join the conversation, and become an exclusive member of Machine Design, create an account today!