Journal: Micromachines

Article Title: Evaluation and Optimization of a MOEMS Active Focusing Device

doi: 10.3390/mi12020172

Figure Lengend Snippet: The large effect of Al stress can be compensated by deposition of an Al-layer with exactly the same stress values and thickness on the back side. In this case, the low membrane distortion without an aluminum reflective layer is recovered, i.e., the membrane part is almost flat.

Article Snippet: The reflective aluminum layers were created by adding the “shell” property offered by COMSOL’s Shell physics module to the corresponding surfaces of the device layer.

Techniques: Membrane

Journal: Sensors (Basel, Switzerland)

Article Title: Axially-Anisotropic Hierarchical Grating 2D Guided-Mode Resonance Strain-Sensor

doi: 10.3390/s19235223

Figure Lengend Snippet: Reflection spectrum obtained from COMSOL ® simulations using the RF module. The ‘ Y -peak’ denotes the peak that shifts under Y -axis strains, and ‘ Z -peak’ denotes the peak that shifts under Z -axis strains. ( a ) solid-disc under Z -axis strain; Note the drop in Y -peak reflectance. ( b ) solid-disc under Y -axis strain; note the Y -peak partially overlaps the Z -peak around 15% strain, and moves past it at 25% strain. ( c ) slotted-disc under Z -axis strain; note the drop in reflectivity of the Y -peak. ( d ) slotted-disc under Y -axis strain; there is a significant drop in Z -peak reflectance.

Article Snippet: The quality factor vs. strain plots ( c,d) were derived from COMSOL ® simulation reflectance plots for 0%–25% strain in steps of 5% strain.

Techniques:

Journal: Scientific Reports

Article Title: Broadband and wide-angle antireflective metasurfaces with complementary patterns

doi: 10.1038/s41598-025-89481-4

Figure Lengend Snippet: Structural details of the fabricated metasurfaces. ( a ) Schematic diagram of preparing metasurface with nanodimple and nanobump designs on PDMS via soft imprint lithography technique. The AFM images of the 3D-PhC, nanodimple layer and nanobump layer are shown as inset in the diagram. ( b, c ) AFM images in 2D view are shown for nanodimple and nanobump metasurfaces respectively. ( d ) Line Profile obtained from the 2D images of the samples. Average height, depth and height respectively of the 3D-PhC, nanodimple and nanobump structures are 121.1 nm, 134.4 nm and 85.3 nm.

Article Snippet: As the cases of Fresnel reflection calculated using the graded index profile (obtained using fill factor from EMT) and FEM calculations of reflectance of metasurfaces using COMSOL used ideal shape of the patterns, these two cases show an increase in reflectance in NIR range.

Techniques:

Journal: Scientific Reports

Article Title: Broadband and wide-angle antireflective metasurfaces with complementary patterns

doi: 10.1038/s41598-025-89481-4

Figure Lengend Snippet: Analysis of antireflection in metasurfaces. ( a ) Schematic of how the nanodimple and nanobump surfaces are modelled for the calculation of effective refractive index. The black dashed line defines the zero height and zero depth in calculation. ( b ) Variation of effective refractive index with height of nanobump surface (red lines) and depth of nanodimple surface (blue lines), calculated using ideal shape of patterns. ( c ) Reflection spectrum calculated using Fresnel’s equation with the index profile from ( b ). ( d ) Variation of effective refractive index with height of nanobump surface (red lines) and depth of nanodimple surface (blue lines), calculated using real shape of patterns from AFM images. Arrows in ( b ) and ( d ) indicate the y-axis corresponding to the data. ( e ) Reflection spectrum calculated using Fresnel’s equation with the index profile from ( d ). The inset shows the measured data. ( e ) Reflection spectra of nanodimple and nanobump metasurface of equal depth and height obtained from COMSOL calculation. In ( b ) and ( d ), height has positive values while depth has negative values due to the choice of z = 0 in ( a ).

Article Snippet: As the cases of Fresnel reflection calculated using the graded index profile (obtained using fill factor from EMT) and FEM calculations of reflectance of metasurfaces using COMSOL used ideal shape of the patterns, these two cases show an increase in reflectance in NIR range.

Techniques: Refractive Index