Herein, this invention disclosure relates to a method to non-invasively monitor printing in-situ. This technique has the ability to monitor a few layers into the material, in a manner that can differentiate between different defect types. This is achieved by utilizing thermal waves to measure the properties during print a few layers below the surface, and reconstruct the characteristic of the layers immediately below. This allows for defects to be easily detected and reworked during production.
- Unlike ultrasounds, a transducer does not need to touch the surface.
- Unlike X-Ray/CT-scanners, technique can be done during build to correct any manufacturing defects before completion.
- X-Ray/CT scanners are extremely expensive and unlikely to be integrated into printers.