Flexible amino acid-based energy harvesting for structural health monitoring of water pipes

Biomolecular piezoelectric materials offer an inexpensive, nontoxic, and renewable alternative to current commercial piezoelectrics, which rely on toxic heavy elements. Currently, there is a lack of testing for real-world applications of these eco-friendly crystals. Here, we validate an amino acid-based sensor capable of real-time detection of pipe leakage, a global challenge for sustainable water access. The polycrystalline device demonstrates data-driven decision making in identifying degraded pipelines, exploiting the relationship between leak-induced vibration and piezoelectric voltage. The device has piezoelectric strain and voltage constants of 0.9 pC/N and 60 mV m/N. Peak voltage of ~2 V is recorded in the low-dielectric film at high flow rates and large leak size. The glycine crystal sensors demonstrate much higher sensitivity than PVDF polymer patches. The sensors can operate over a range of test leak sizes, with the energy content of the worst leak state being >10 times that of a healthy pipe.