Local Stress Sensing using Tetrapod Nanocrystals
Schematic of a tetrapod-polymer film before and after uniaxial tensile deformation (upper image). Modeling of the nanoscale stresses in tetrapods under uniaxial deformation reveals the stress states which lead to compression- and tension-sensing, both crucial for detecting nanoscale crack formation (lower image).
Tetrapod nanocrystal stress sensors have been embedded into structural films and simultaneous opto-mechanical tensile testing revealed new sensing modalities with orders of magnitude improved sensitivity to detect stress.
Significance and Impact
This approach can sense stress at the nanoscale, the length scale on which cracks develop before failure. The fabrication techniques are readily scalable to industrial processing, and the nanocomposite stress sensors are comparable to, or exceed, current stress sensing technologies.
- Calculations were performed using finite element micromechanical modelling and ab initio density functional theory to reveal the scientific mechanisms at the nanoscale underlying the highly sensitive capability to local sensing stresses in structural films.