Chemists from Israel and China have developed a functionalised electrode that acts as a memory element for encoding and processing information.

Itamar Willner at the University of Jerusalem and colleagues created an on/off switch by modifying a gold electrode with an organic monolayer that responds to electrochemical and photochemical stimuli.

An on/off system of elements is the basis of standard electronic computers. For chemical-based approaches to have any practical utility, they must be integrated with systems that enable the read-out of the stored data.

Willner encoded the information by electrical stimulation that shifts the molecules of the monolayer into a certain conformation. This encoded information is then read out as a change in the electrochemical properties of the electrode. 

The stored information can be then be erased by irradiation with light of a particular wavelength that transforms the molecules back to their original state.

The vast range of chemical compositions and structures offered by organic molecules could encode tremendous amounts of information, according to the team. 

'There is continuous interest in developing smart materials that perform logic functions and arithmetic operations. Such systems are considered potential chemistry-based computers.' Willner said.

He said that their work 'will encourage organic chemists and material scientists to synthesise smart materials that can perform functions of higher complexity and variability.'

Michael J Spencelayh