Semi-Biological Photovoltaic Cells

Lead Research Organisation: University of Cambridge
Department Name: Chemical Engineering and Biotechnology


In this application we aim to harness photosynthesis, a fundamental biological process, and use it to convert natural sunlight into a utilisable form of energy with a biological photovoltaic panel. Using a multidisciplinary approach, we intend to prove the feasibility of biological photovoltaics for the production of hydrogen and/or electricity. A large amount of work has already been carried out in thefield of biological hydrogen production, but so far it has proven to be difficult to overcome the major technical hurdle that limits the commercialisation of this technology, namely that the oxygen produced during photosynthesis inhibits the production of hydrogen from the hydrogenase enzyme in vivo. Although there has been some interest in fabricating artificial devices with purified protein complexes to overcome this problem, these have not yet been shown to be economically feasible. In this application, we propose to separate the processes of oxygenic photosynthesis and hydrogen production in a semi-biological photovoltaic device using intact Gloeobacter cells. The device will essentially be composed of two chambers, or half-cells, so that biological material can harvest light energy in one chamber, and hydrogen can be produced in a second anaerobic chamber. This electrochemical approach to biological hydrogen production physically separates photosynthesis from hydrogen evolution, and by doing so, it prevents the oxygen produced during photosynthesis from inhibiting the production of hydrogen. In addition, this electrochemical approach can be used to produce a DC electrical current, in a manner analogous to standard silicon based photovoltaic panels; in this application we will also explore the potential of biological photovoltaic panels for the production of electricity.
Title Visualisation of Semi-Biological Photovoltaic Cells 
Description In conjunction with the prototype reactor development for the Royal Society Summer of Science Exhibition a video demonstrating design concepts and the underlying mechanism of electricity generation for these devices was developed in collaboration with a commercial software company. 
Type Of Art Film/Video/Animation 
Year Produced 2010 
Description The research feasibility programme explored the prototype design and construction of a biological photovoltaic device. A key motivator for the technology is the opportunity to develop significantly lower cost photovoltaic devices which can also be applied on larger scales than existing PVs. The project brought together researchers from chemical engineering and biochemistry, key programme findings include:

Prototype reactors composed of two electrochemical half cell components were designed and constructed, to form a device to harvest sunlight light in the anodic chamber using algal substrates. A cathodic chamber allowing recombination of the protons released as part of the water splitting reaction in the anode was separated from the anodic chamber using a proton exchange membrane. The design and construction of the reactors was carried out using microfabrication techniques to create well defined precise reactor geometries to allow analysis of the photocurrent/voltage characteristics to be investigated. The prototype reactors constructed delivered an electrochemical cell which produced a DC electrical current under illumination and also a residual background DC current from the algal substrates analogous to microbial fuel cell type systems. The application of the developed devices for the cogeneration of a chemical biproduct (hydrogen) in the cathodic chamber was also investigated.
Exploitation Route The project highlights the potential of these technologies for application in the bioenergy sector. An example of new developments of the approaches is an ongoing activity with collaborators at the University of Malaya.
Sectors Education,Energy

Description Prototype biophotovoltaic (bpv) devices have been developed and exhibited to the public to demonstrate the production of electricity by tapping into the ability of algae or cyanobacteria to harness solar energy. In the prototype reactors developed, electricity was generated by growing a film of photosynthetic cells onto a transparent conductive electrode which becomes the anode of a two chamber electrochemical cell.
First Year Of Impact 2011
Sector Education
Impact Types Societal