Sweat permeable and ultrahigh strength 3D PVDF piezoelectric nanoyarn fabric strain sensor

TLDR

Commercial wearable piezoelectric sensors are highly stable but their electronic packaging makes them non‑breathable, reducing comfort. The study aims to create a breathable, high‑strength PVDF nanoyarn 3D piezoelectric fabric sensor that offers a strategy for comfortable flexible wearables. They weave ultrahigh‑strength PVDF nanoyarns into a 3D textile to produce a breathable piezoelectric fabric sensor. The resulting 3DPF sensor achieves a tensile strength of 46.0 MPa, the highest reported for flexible piezoelectric sensors, and exhibits rapid unidirectional sweat transport, maintains or improves piezoelectric performance during sweating, and matches cotton T-shirts in durability and comfort.

Abstract

Abstract Commercial wearable piezoelectric sensors possess excellent anti-interference stability due to their electronic packaging. However, this packaging renders them barely breathable and compromises human comfort. To address this issue, we develop a PVDF piezoelectric nanoyarns with an ultrahigh strength of 313.3 MPa, weaving them with different yarns to form three-dimensional piezoelectric fabric (3DPF) sensor using the advanced 3D textile technology. The tensile strength (46.0 MPa) of 3DPF exhibits the highest among the reported flexible piezoelectric sensors. The 3DPF features anti-gravity unidirectional liquid transport that allows sweat to move from the inner layer near to the skin to the outer layer in 4 s, resulting in a comfortable and dry environment for the user. It should be noted that sweating does not weaken the piezoelectric properties of 3DPF, but rather enhances. Additionally, the durability and comfortability of 3DPF are similar to those of the commercial cotton T-shirts. This work provides a strategy for developing comfortable flexible wearable electronic devices.