The global market for piezoelectric materials, which generate an electrical potential when squeezed, is estimated at $1bn per annum. That’s big business and with a wide variety of applications including sensors and smart structures it will only get bigger. There’s just one catch – lead zirconate titanate (PZT) on which the majority of commercial piezoelectric devices are based is toxic.
Potassium sodium niobate (KNN) has been proposed as an alternative material to replace PZT but until now there has been no comprehensive environmental sustainability assessment to justify this switch.
Adolf Acquaye and his co-authors extend a hybrid life cycle assessment with additional sustainability metrics to compare the merits of PZT vs KNN. Without this type of sophisticated assessment comparison is nebulous because we know that environmental impacts can conveniently shift to other phases of a material’s lifecycle. In fact, the overall environmental impact of KNN far outweighs that of PZT due to the presence of niobium, the extraction of which at the beginning of the lifecycle results in a high overall environmental impact.
Ibn-Mohammed, T., Koh, S. C. L., Reaney, I. M., Acquaye, A., Wang, D., Taylor, S., and Genovese, A. 2016. Integrated hybrid life cycle assessment and supply chain environmental profile evaluations of lead-based (lead zirconate titanate) versus lead-free (potassium sodium niobate) piezoelectric ceramics. Energy & Environmental Science, Advance article: http://dx.doi.org/10.1039/C6EE02429G.