Portable device integrating an ultrasensitive mechanical crack-based sensor for the wireless monitoring of cardiac activity

Flexible crack-based strain sensors showing a maximum gauge factor of 30,000 at 0.2% strain level are elaborated by means of Atomic Layer Deposition and e-beam evaporation. It is shown that the mechanosensitivity can be drastically boosted by encapsulating the cracks with a photoresist layer. A non-invasive portable device integrating this ultrasensitive flexible transducer is then developed to monitor the cardiac activity at rest. The presented prototype integrates a Bluetooth Low Energy wireless interface for real-time communication with an Android mobile device.