ITM’s unique technology allows a wide range of material properties to be engineered into its ionomeric polymers.  As previously announced, these materials can be made with either acid or alkaline properties, while in addition the materials developed specifically for the Alcohol Fuel Cell Programme (announced on 30th August 2005) included variants produced by radiation graft processes which facilitate the production of thin films in a range of mechanical strengths and water contents.  The ability to control and engineer the properties of the Company’s materials has now led ITM to two, potentially significant, improvements to fuel cell systems:

(i)  Composite membranes. These are membranes in which one side of the membrane can be composed of an acidic polymer, while the other side is composed of an alkaline polymer.  Such a system is more costly to make because it builds on a pre-existing membrane, but it enables the separate choice of different catalysts on each side of the cell.  For example, one catalyst chosen to operate in an acid environment with the fuel, while a second (different) catalyst operates in an alkaline environment with the oxidant.  Because the cost of a cell depends both upon the cost of the membrane and of the catalyst, the overall system can show economic and efficiency benefits even allowing for the increased cost and complexity of the membrane structure.  Composite membranes potentially reduce the overall cost of a fuel cell system by raising efficiency, reducing catalyst costs and simplifying hydration control systems.

(ii)  Direct electrical control of fuel cell power output.  Conventional fuel cells work well when operating steadily at full power, but the methods available to change the power output or sustain operation at part load are problematic.  There are two existing strategies to address this issue: firstly, to restrict the fuel supply, but in doing so only part of the cell or cell stack operates while the rest 'idles'. This results in thermal and hydraulic stresses in a single cell and the possibility of 'cell reversal' in a stack - a potentially serious problem.   A second widely used method of control is to provide excess fuel and allow all the cells to operate at all times.  This prevents damage to the cells but involves a complex balance of plant to recycle the excess fuel and control the output of the stack electronically.  Neither process is entirely satisfactory.  Control problems represent a major (and costly) obstacle to the use of fuel cells in situations (such as road vehicles) where rapid control of output is essential.

ITM has demonstrated direct electronic control of a fuel cell by incorporating a control grid into the junction between the two layers of a composite membrane.  The result is in some ways analogous to the control grid used in electronic valves or transistors although here it is the flow of ions which must be controlled, not electrons.  It is the availability of a composite acid/alkaline membrane, as set out above, which has made possible the practical demonstration of the control grid concept. 

The Company has filed patent applications both on the invention of a composite membrane of enhanced properties including specifically an acid/alkaline laminate; and on the use of control grids to act directly on and control the electrical activity within a fuel cell.  This technology has the potential to improve the efficiency of fuel cells and offers a unique route to controlling the output from a fuel cell.  ITM considers that these developments represent a significant addition to the long term value of its intellectual property portfolio and could be of considerable potential value to the Company. 

Commenting, Jim Heathcote, Chief Executive of ITM, said, “We believe that these developments represent an historic scientific advance.  The breakthroughs announced today help address some fundamental barriers to the adoption of fuel cells including hydration control, improved lower cost catalysis, higher efficiency and direct rapid electronic control over power output through what is effectively the world’s first “ionic transistor”.   

“ITM is currently focused on proving the technology it has developed to make low cost and durable fuel cells or electrolysers prior to commercial exploitation.  During this phase of the Company’s development, we are continuing to file important patent applications that greatly increase our intellectual property portfolio and consequently our value.  Our objective is the development of convenient and cost competitive systems that can rapidly enter the commercial marketplace. We consider that these fundamental inventions significantly increase the value of our patented technology to future licensees and increase our probability of successfully exploiting our intellectual property for shareholders.”