Next-generation 2D optical strain mapping with strain-sensing smart skin compared to digital image correlation

Abstract

This study reports next generation optical strain measurement with “strain-sensing smart skin” (S4) and a comparison of its performance against the established digital image correlation (DIC) method. S4 measures strain-induced shifts in the emission wavelengths of single-wall carbon nanotubes embedded in a thin film on the specimen. The new S4 film improves spectral uniformity of the nanotube sensors, avoids the need for annealing at elevated temperatures, and allows for parallel DIC measurements. Noncontact strain maps measured with the S4 films and point-wise scanning were directly compared to those from DIC on acrylic, concrete, and aluminum test specimens, including one with subsurface damage. Strain features were more clearly revealed with S4 than with DIC. Finite element method simulations also showed closer agreement with S4 than with DIC results. These findings highlight the potential of S4 strain measurement technology as a promising alternative or complement to existing technologies, especially when accumulated strains must be detected in structures that are not under constant observation.

Mechanically and Thermally Guided, Honeycomb-like Nanocomposites with Strain-Insensitive High Thermal Conductivity for Stretchable Electronics

“…To probe the cause of the sudden temperature change, digital image correlation (DIC) 55 was employed to analyze the strain distribution of the compact sample during stretching from 0 to 300% (Figure 4c and Video S3). The strain distribution of the compact sample was uniform without any local image distortion when the strain was below 200%.…”

Research on microstrain loading device and strain detection method based on SWCNT strain sensor

“…The emitted light will disappear when the excitation light turns off. The light generated under excitation light is called fluorescence, and the material that can emit fluorescence is called fluorescent material [7][8][9][10][11]. The nano thin film made of photo-luminescent material single-walled carbon nanotubes (SWCNT) can achieve precise measurement of micro-strain and has broad application prospects.…”

A concept for a large-scale non-contact strain measurement system using nanostructures

“…al. presented a method based on single-wall carbon nanotubes which showed an dependency between the strain and their infrared response spectra [7]. Another promising setup used structural colors, a class of dyes with a tendency to self-organize, which create color impressions starting at a given strain level [8,9].…”