Super-compressible, fatigue resistant and anisotropic carbon aerogels for piezoresistive sensors
Carbon aerogels combining excellent mechanical performance and conductivity have been increasingly developed for various applications. However, most carbon aerogels are unable to meet requirements for compressibility and fatigue resistance, greatly restricting their applications as strain sensors. Here we apply the bidirectional freezing technique to fabricate graphene and nanocellulose carbon aerogels with the hierarchical structure and oriented pores. The regular architecture combined with the synergistic effect of graphene and cellulose carbon nanofibers make the carbon aerogels reveal a series of mechanical properties, including a high compressibility up to 90%, and high fatigue resistance with a plastic deformation of 8.2% at 50% strain after 10,000 cycles. Moreover, the obtained carbon aerogel exhibits a low density of 3.26 mg cm−3 and the high electrical conductivity of 0.32 S m−1. Considering the high compressibility, superior fatigue resistant and high electrical conductivity, the carbon aerogels are assembled to make flexible strain sensors with high sensitivity of 0.26 kPa−1. The sensor was used to make a pedometer (walking step counter) and accurately monitor human activity, demonstrating potential for use in wearable devices.
KeywordsBidirectional freezing process Celluloses Graphene oxide Piezoresistive sensors
This work was supported by the National Key Research and Development Program of China (2017YFD0601004), State Key Laboratory of Pulp and Paper Engineering (201750), and National Natural Science Foundation of China (21404011, 21674013).
Compliance with ethical standards
Conflict of interest
All authors declare that they have no conflict of interest.
- Bai H, Chen Y, Delattre B, Tomsia AP, Ritchie RO (2015) Bioinspired large-scale aligned porous materials assembled with dual temperature gradients science. Advances 1:e1500849Google Scholar
- Chen QY, Cao PF, Advincula RC (2018b) Mechanically robust, ultraelastic hierarchical foam with tunable properties via 3d printing. Adv Funct Mater 28:1800631. https://doi.org/10.1002/adfm.201800631/Adfm.201800631 CrossRefGoogle Scholar