Material Disruption Ahead

By: Sheila Moorcroft

New materials and processes are proving effective against a growing range of bacteria and have wide ranging applications. Similar approaches may also change the way we clean our clothes and how often we paint our houses. They could also prove disruptive to existing sectors’ income streams.

What is changing?

Hospitals and nursing homes are vulnerable to bacterial infections and an increasing number of those infections are showing signs of resistance to antibiotics with significant repercussions in terms of deaths and other costs. A number of new developments are set to help – by variously reducing the ability of bacteria to take hold on surfaces, or rapidly removing any that are there.

Prevention first

Self cleaning glass has been on the market for some years; its treated surface reducing the ability of dirt to stick and then helping water to wash it off the next time it rains. Similar principles are being applied to prevent bacteria sticking to surfaces.

A new process can apply a nano-layer of glass to surfaces from door handles to bedside tables, trolleys to lift walls and floors. Field tests so far indicate up to a 50% reduction in the presence of bacteria.

Elsewhere research is examining the potential of a combination of soot and silica to provide self cleaning properties to surfaces such as touch screens, windows and lenses. This combination repels both oil and water; such properties may also reduce infections.

Faster and more effective removal

Silk treated with a form of chlorine for just one hour and then allowed to dry was shown to kill E. Coli bacteria within 10 minutes, and was even effective against Anthrax spores which are a much more difficult target.

Similarly, a new nano-cotton filter material could ‘zap’ bacteria with a very low level voltage and clean water in minutes. In lab experiments, the filter killed some 98% of E. Coli in water samples. The use of very low voltage could make safe water affordable and feasible in remote village in emerging and developing countries, using solar chargers.

Paint could help to kill superbugs on walls and doors, when the fluorescent lights are turned on. Nano-particles of titanium oxide in the paint react with UV (Ultra Violet) light and kill bacteria including E. Coli; however, other paint additives at present reduce that capability.

UV light also helps clean keyboards. The growth of electronic records has brought shared keyboards into hospitals and care homes by the thousand and with them the risk of rapid cross infection if bacteria are present among users. At the wave of a hand, the new keyboard ‘self cleans’ by retreating into a specially designed UV light bath within an otherwise dark box, and pops out again for the next person.

Why is this important?

We may be facing many a positive but also potentially disruptive material revolution.

The cost of MRSA alone in American hospitals in 2007 was put at $45 billion, with an estimated 1 million cases and 100,000 deaths – although some estimates put the numbers much lower – 94,000 cases and 18,650 deaths in 2005. In the UK, a major campaign against MRSA appears to be having a positive impact with numbers reducing, but bacterial infections of many kinds remain a constant and growing problem for hospitals and other care environments. Finding more effective solutions remains a high priority.

Such developments may not only help hospitals but food processing, pharmaceutical production, sterile manufacturing for electronic production and the emerging bio-industries as well. Shared machines such as cash dispensers or public transport may also use such technologies to improve cleanliness and reduce infection risks.  But, they may also have adverse consequences for some. The cleaning products markets is big business; worth about £2.5 billion in the UK alone.  Technologies which radically reduce demand could significantly disrupt the income streams of some major companies, long term.

And similar techniques are being applied to more mundane problems. Self cleaning paints, it is claimed, could significantly reduce the frequency with which we need to paint our homes or other surfaces. Silk and cotton treated with nano-particles of titanium oxide could also respond to sunlight, ‘digesting the dirt and stains’ and so remove the need for washing and dry cleaning. Sunbathing may take on a whole new meaning!

By Sheila Moorcroft