Highly Transparent and Transferable Ultralong Carbon Nanotube Networks for Transparent Wearable Electronics.

Abstract

Recent advances in transparent wearable electronics highlighted the need for flexible conductive layers with high transmittance. Carbon nanotubes (CNTs) are ideal candidates for constructing transparent conductive networks due to their excellent flexibility, desirable optical properties, and outstanding electrical characteristics. However, their performance is severely degraded by the junction resistance between individual CNTs. Herein, we prepared nearly invisible and transferable ultralong CNT conductive networks with high transmittance (>99% at 550 nm). The centimeter-scale length of ultralong CNTs facilitated the successful assembly of conductive and suspended networks with a minimal thickness, absorption area, and junction density, enabling ultrahigh transmittance and transferability. Further, we developed an ultralong CNT-based flexible and transparent pressure sensor to verify their practical value. The sensor exhibited a high sensitivity (225.11 kPa-1), a broad operating range (up to 160 kPa), a rapid response time (11 ms), and robust stability over 10,000 cycles, outperforming most state-of-the-art transparent pressure sensors. This work shows the promising application potential of ultralong CNTs in high-performance transparent wearable electronics.