Microelectromechanical systems (MEMS) are becoming more advanced and consist of many different layers.

This poster explains the testing techniques used to measure the internal structures of MEMS, which can be difficult to characterise. Non-contact and non-invasive techniques (Optical Coherence Tomography and Infra-red Confocal Microscopy) were used to assess the thickness of different layers in an example MEMS pressure sensor.