Sensory capabilities of substances analysis of piezoelectricity for healthcare

This study reviews piezoelectric tracking sensor fundamentals and recent advances in materials and composites for detecting human motion. Piezoelectric sensors convert mechanical stress into electrical signals, enabling detection of both small and large human movements. Their flexibility, conformability, and mobility make them suitable for wearable health monitoring and personalized healthcare. However, instability in extreme pH environments limits performance. To address this, a flexible GaN nanoplate-based sensor was developed, showing excellent stability and linearity retaining 99% of its initial performance after 40 days in air and across pH 1–13. Leveraging its strong piezotronic performance, the device effectively detected various motions such as eating, knee bending, and wrist movement. It was also applied to intelligent fall monitoring and gesture recognition. A smart fall warning system incorporated with machine learning analyzed activity data for senior healthcare. Vibrations from falls were detected as electrical signals, distinguishing falling from daily activities like standing, sitting, walking, and crouching. Using a k-nearest neighbor (k-NN) classifier, the system achieved 100% accuracy in differentiating falling from non-falling events. This research highlights the potential of durable, flexible electronics for intelligent, personalized health monitoring applications.