Two dimensional carbon nanotube based strain sensor

This paper presents a 2-dimensional carbon nanotube (CNT) strain sensor with high sensitivity. The sensors, single-walled CNTs and multi-walled CNTs synthesized by thermal chemical vapor deposition, are grown directly on the suspended cantilever beams to measure external strain. The design of the sensor allows effective adhesion between CNTs and the cantilever beams, which results in CNT lengthwise strain and piezo-resistivity change. The suspended cantilever beams are fabricated by micromachining techniques. Experimental results show that the sensor achieves a high strain resolution of 0.00099%. The maximum piezo-resistivity gauge factor of the sensor is 744. The two-dimensional strain sensor presents the advantage of high sensitivity, which is beneficial for integration in a CMOS process of mass production.