Hydrophobic, elastic and conductive O-BC/MXene aerogel with high sensing performance

Hydrophobic, elastic, and conductive (HEC) aerogels have significant potential in electronic devices. Herein, we propose a new method to fabricate an HEC aerogel with excellent mechanical and sensing performances from TEMPO-oxidized bacterial cellulose (O-BC) and conductive MXene nanosheets via directional freeze-drying and silanization modification. O-BC with a high aspect ratio can interweave with each other to form continuous layers, while MXene can induce a regular and flat structure and provide good conductivity. The silanization modification ensures high hydrophobicity and high elasticity, which can prevent the aerogel from structural collapse by avoiding adhesion among lamellae. The resulting aerogel can withstand compressive strain high up to 90% and long-term compression for 10,000 cycles at 50% strain due to the elastic and hydrophobic lamellar structure. It also offers a precise electrical response to stress signals in a broad detection range of 0–40 kPa and can accurately detect biological signals from humans. These structural and mechanical performance benefits make the HEC aerogel valuable in the field of pressure sensing.