Layer-by-layer self-assembly of durable, breathable and enhanced performance thermoelectric fabrics for collaborative monitoring of human signal

Thermoelectric devices have received widespread attention in next-generation flexible electronics due to their excellent self-powered characteristics, multifunctionality and high integrability. However, current thermoelectric devices suffer from drawbacks such as poor durability, complex preparation processes, and terrible air permeability which is the necessary metric in wearing comfort. Here, we propose a layer-by-layer (LBL) self-assembly strategy to prepare multifunctional thermoelectric fabrics with enhanced thermoelectric performance and durability. Based on the self-assembly effect, the interfacial bonding between the thermoelectric material and the fabric substrate is effectively improved, so that the thermoelectric properties of the fabrics can still be maintained stable after 2000 bending cycles and 600 washing cycles. Moreover, this strategy increases the electrical conductivity of the fabric by a factor of 4 without affecting the fabric's air permeability (up to 400 mm s−1 at 50 Pa) and tensile properties (strains exceeding 100 %). Due to its wearability and multifunctionality, the fabric was designed as a synergistic monitoring system that includes facial respiration monitoring and knee joint motion monitoring for continuous monitoring of the athlete's dynamic body condition. This thermoelectric fabric shows amazing potential for advanced smart textiles, soft robotics and human–computer interaction.