As all my friends leave Groningen for the summer, I’m feeling lucky to still be here beneath the beautiful grey skies; if only because the weather in the UK is usually even worse. Now that I’ve been freed from the shackles of Chemistry for a few months, I wanted to head back into the university to find out what kind of research is going on in the world of energy. Being an aspiring scientist, I really need a path to follow, and after talking to Professor Beatriz Noheda of the Zernike Institute for Advanced Materials, I’ve found a topic which has certainly piqued my interest: piezoelectric energy harvesting.
Like most words and symbols in science, piezoelectric has roots in the Greek language, with ‘piezo’ meaning ‘to push’. Essentially it is a method of harvesting energy through the application of pressure. There are also many other uses for these piezoelectric materials, such as in sonar, ultrasound or even in vending machines, however at Energy Academy Europe we like to focus on all things energy. Beatriz told me that the main idea with energy harvesting is having self sufficient devices; giving pressure sensors in car tyres as one example. The sensors will measure the pressure and at the same time utilise the vibrations of the moving car to power itself. This is a win-win when it comes to reducing the carbon footprint of the vehicle as the tyre pressure itself affects energy usage.
Unfortunately there are a few downsides to using these materials in a broader sense at the current time, one of which is due to the relative toxicity of piezoelectric materials, as the best are lead containing. This is the topic Beatriz focuses on, studying and investigating the properties of these lead based materials, to understand why they’re effective and to hopefully find less toxic alternatives. The benefits of this? Though piezoelectrics have a low energy density when compared to solar (~100x less, you need a surface 100x bigger to produce the same energy) they have the advantage in that they don’t require the sun and can be hidden from sight; though of course you don’t want that much lead plastered around. Nonetheless, I’m imagining a future in which our pavements are lined with these devices, lighting our way as we pass as well as dancefloors flickering in response to footsteps.
Given the low energy density of piezoelectric materials, it will certainly be a while before there is wide spread application of the energy harvesting technique. As our technology moves forward, the energy our devices use also decreases and so further down the line we could end up having a Tinder style situation where energy usage and energy density match. To me, this seems like a technology of the future, made all the more exciting by the fact that it is related to one of my favourite topics so far – Inorganic Chemistry. For the present I’m just preparing myself to be like a piezoelectric material for the coming academic year: effective under pressure.