DNA-Like Double-Helix Wrinkled Flexible Fibrous Sensor with Excellent Mechanical Sensibility for Human Motion Monitoring

Flexible mechanical sensors offer extensive application prospects in the field of smart wearables. However, developing highly sensitive, flexible mechanical sensors that can simultaneously detect strain and pressure remains a significant challenge. Herein, we present a flexible mechanical sensor based on AgNPs/MWCNTsCOOH/PDA/PU/PVB nanofiber-covered yarn (AMPPPNY) featuring a DNA-like double-helix wrinkled structure. The sensor is fabricated by electrospraying polyvinyl butyral (PVB) onto a pre-stretched double-helix elastic yarn, followed by electrospinning a polyurethane (PU) nanofiber membrane and inducing the self-polymerization of dopamine (DA) to create an adhesive layer. Then, one-dimensional carboxylated multi-walled carbon nanotubes (MWCNTs-COOH) and zero-dimensional silver nanoparticles (AgNPs) are dispersed onto the structure, synergistically forming a stable conductive network for efficient signal transmission. The integration of conductive fillers with different dimensionalities and DNA-like double-helix wrinkled structure endows the sensor with high strain sensitivity (gauge factor of 11,977) in the strain range of 0–310% and high pressure sensitivity (0.475 kPa⁻¹) in the pressure range of 0–2 kPa. Moreover, the fabricated sensor exhibits rapid response and recovery times (130 ms/135 ms) and outstanding cyclic stability (over 10,000 cycles of both strain and pressure). Next, the fibrous sensor is weaved into a large-area fabric, and the developed smart textiles demonstrate impressive performance in detecting both subtle and large human movements. The proposed sensor is a promising candidate for flexible wearable applications.

Graphical Abstract