High sensitivity graphene based health sensor with self-warning function.

In order to reduce the damage to people's health from diseases that attack the respiratory system such as COVID-19, asthma, and pneumonia, it is desired that patients' breathing can be monitored and alerted in real-time. The emergence of wearable health detection sensing devices has provided a relatively good response to this problem. However, there are still problems such as complex structure and poor performance. This paper introduces a laser-induced graphene (LIG) device that is attached to PDMS. The LIG is produced by laser irradiation of Nomex and subsequently transferred and attached to the PDMS. After being tested, it has demonstrated high sensitivity, stable tensile performance, good acoustic performance, excellent thermal stability, and other favorable properties. Notably, its gauge factor (GF) value can reach 721.67, which is quite impressive. Additionally, it is capable of emitting an alarm sound with an SPL close to 60 dB when receiving signals within the range of 5-20 kHz. The device realizes mechanical sensing and acoustic functions in one chip, and has a high application value in applications that need to combine sensing and early warning.