Flexible Capacitive Synapse with Ultralow Energy Consumption Enabled by a Freestanding BaTiO ₃ Membrane

The development of wearable neuromorphic devices demands materials with remarkable ferroelectric behavior, mechanical flexibility, long-term stability, and cost-effective processing. This study demonstrates that employing a water-assisted exfoliation strategy yields an ultrathin, flexible BaTiO 3 membrane that can be readily transferred to a variety of substrates for constructing a van der Waals-based capacitive artificial synapse. The fabricated device demonstrated outstanding environmental stability and retained a clear ferroelectric hysteresis even at an operating voltage of 50 mV, enabling ultralow energy consumption. Integration into a synapse-based system for electrocardiogram classification, including arrhythmia recognition, further highlights the applicability of flexible functional oxide thin films for high-performance wearable sensing technologies.