Polysiloxane Interface‐Engineered Flexible n‐Type Thermoelectric Aerogels for Intelligent Perception and Energy Harvesting

ABSTRACT Aerogels have emerged as a promising class of thermoelectric materials owing to their unique structural characteristics. However, developing n‐type thermoelectric aerogels with efficient energy conversion and mechanical flexibility remains challenging. Herein, a novel interfacial engineering strategy is proposed to fabricate high‐performance n‐type thermoelectric aerogels. By constructing poly(3‐glycidoxypropyltrimethoxysilane) (PGPTMS) molecular bridges at the Ti 3 C 2 T x MXene/CSWCNT heterointerface via covalent bonding, a stable p‐n transition and enhanced mechanical flexibility are simultaneously achieved. The resulting n‐type aerogel with a multiscale hierarchical architecture exhibits a Seebeck coefficient of −53.6 µV K −1 , high electrical conductivity (6.39 S cm −1 ), low thermal conductivity (37.3 mW m −1 K −1 ), and ultralow density (12 mg cm −3 ), along with a room‐temperature zT value of 0.015 and 99.2% height retention following 1000 cycles. By assembling the n‐type aerogel with its p‐type counterpart, an aerogel thermoelectric generator is developed, delivering a gravimetric power density of 17.2 µW g −1 at Δ T = 40 K and temperature‐sensing performance with a resolution of 0.002 K. Based on this, an intelligent robotic finger for material identification and a noncontact encryption system are demonstrated. Moreover, scalable integrated devices show promise for energy harvesting and self‐powered electronics. This study provides novel insights into the design and application of high‐performance n‑type thermoelectric aerogels.