Getting Steamy with Solar Energy

Jonathan Strickland

© Corbis
© Corbis

I read this morning over at Science Daily about a project that could help billions of people in developing countries live in healthier environments. The Bill and Melinda Gates Foundation provided funding for the project and its goal was non-trivial: Find a way to provide sanitation and sterilization techniques to communities that may not have access to things we take for granted, like electricity.

The solution had lots of qualifiers -- you couldn't just nuke germs, microbes and other nasty stuff from orbit or anything. It had to be easy to implement and not involve dangerous components that could harm those operating the systems. The solution that lead researcher Naomi Halas and her team came up with was harnessing the energy of the sun itself to do the work.

It all comes down to special nanoparticles. On the nanoscale, stuff we're familiar with can start to exhibit surprising qualities. A toxin might become harmless or a harmless substance could become deadly. Halas and her team engineered a nanoparticle that converts a broad spectrum of light into heat. And it does it so quickly that if you submerge the nanoparticles into ice water they can convert it into steam in the blink of an eye. That steam gets really hot -- hot enough to kill bacteria and viruses.

The techniques will be used in two broad applications. The first is sterilizing medical instruments, which will help cut back on infection. The other is to sanitize human waste. And because it harnesses solar energy directly, there's no need to hunt around for an outlet to plug it in.

I find Halas's work to be really inspiring. It's another example of how learning more about our universe -- in this case, what happens at incredibly tiny scales -- can benefit us in unimaginable ways further down the line.