an MIT research team has developed a way to print functioning solar cells on ordinary paper, cloth, and plastic, which can be folded even into a paper airplane without loss in performance (the folding of a paper-based solar cell into a paper airplane was accomplished in fall of  2010, in the early stages of research leading to the current project)

a team of researchers at MIT has developed a means of printing highly resilient, functioning solar cells on ordinary paper, cloth, and other materials, which can be folded and laminated without any appreciable loss in performance. the team is led by professors karen gleason and vladimir bulović and graduate student miles barr.

until this point, the production of solar cells has required the exposure of substrates to liquids or high temperatures, which would damage ordinary materials like paper, cloth, or plastic. instead, the new system utilizes vapors and temperatures under 120°C. in a vacuum chamber, five successive layers of material are deposited onto the substrate, utilizing a mask composed of paper to form the proper patterns for the photovoltaic array.

printable foldable solar cells - 2 a solar cell printed onto paper

the solar cells produced by this method are highly resilient. the MIT folded and unfolded 1,000 times a sheet of PET plastic onto which a solar cell had been printed, with no significant loss of performance; by contrast a commercially produced solar cell on PET plastic failed after a single folding. the team has also coated printed paper in laminates and tested the cell in the high temperatures of a laser printer without a decrease in performance, opening up the option of outdoor, weather-resistant applications. while formal longevity studies have yet to be conducted, test cells that the team produced last year are still functioning.

printable foldable solar cells - 3 left: a printed sheet; right: a printed cell is tested being folded and unfolded while connected to a voltometer

while the current research did not focus on optimization, with the printed cells achieving an efficiency of about 1%, bulović notes that because of the low weight of paper or plastic compared to the standard glass substrate used in solar cell production, ‘we think we can fabricate scalable solar cells that can reach record-high watts-per-kilogram performance’. the extremely low materials cost, combined with the ease of transport afforded by the light weight of the cells, may have expansive use in developing world applications.

the work was supported by the eni-MIT alliance between the university and italian energy company eni.

video depicting a paper solar cell circuit powering an LCD clock

video depicting the folding and unfolding of a paper solar cell circuit during testing

the mit press release via next big future