Effective Growth of Pure Long-Straight Boron Nitride Nanowires Strain and Application as Flexible Humidity Sensor

Abstract

Boron nitride nanowires (BNNWs) with high purity and a long-straight fashion are synthesized via ball milling and annealing technique at 1150°C successfully. These nanowires have an average length of more than $50\mu \text{m}$ with diameter 100 nm. The results of characterization showed that the main elements of the nanowires are boron and nitrogen, which molar ratio of B:N is close to 1 indicating the BN structure. The electrical properties of an individual BNNW were studied for the first time. The resistivity, carrier concentration, and carrier mobility of raw BNNWs were drawn from the experimental I-V curves. In addition, extremely stretchable BNNW networks two-terminal devices were fabricated on flexible and transparent elastomeric substrates. The electrical and mechanical properties of these devices were firstly investigated by bending tests. The as synthesized products were utilized as sensing material to detect strain and humidity. Results show that their electrical resistance increased with bending and humidity, proving the feasibility of the wearable human-friendly strain sensor and humidity sensing system. Our results indicate that BNNW networks are potential wearable sensor or medical integration of electronic implants.