A Review: Carbon Nanotube-Based Piezoresistive Strain Sensors

Figure 2

The primary gap Δ𝐸^1𝑔 (semiconducting single-walled carbon nanotubes) scales as 1/𝑟 (a), while for the curvature-induced band gap Δ𝐸^2𝑔 (small-gap semiconducting carbon nanotubes) scales as 1/𝑟². At Δ𝐸^1𝑔 = Δ𝐸^2𝑔 = 0 relates to armchair nanotubes, which maintain their metallic character [4].

(a)

(b)