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A nanometre-scale resolution interference-based probe of interfacial phenomena between microscopic objects and surfaces.

Contreras-Naranjo JC, Ugaz VM - Nat Commun (2013)

Bottom Line: Interferometric techniques have proven useful to infer proximity and local surface profiles of microscopic objects near surfaces.But a critical trade-off emerges between accuracy and mathematical complexity when these methods are applied outside the vicinity of closest approach.Here we introduce a significant advancement that enables reflection interference contrast microscopy to provide nearly instantaneous reconstruction of an arbitrary convex object's contour next to a bounding surface with nanometre resolution, making it possible to interrogate microparticle/surface interaction phenomena at radii of curvature 1,000 times smaller than those accessible by the conventional surface force apparatus.

View Article: PubMed Central - PubMed

Affiliation: Artie McFerrin Department of Chemical Engineering, Texas A&M University, College Station, Texas, USA.

ABSTRACT
Interferometric techniques have proven useful to infer proximity and local surface profiles of microscopic objects near surfaces. But a critical trade-off emerges between accuracy and mathematical complexity when these methods are applied outside the vicinity of closest approach. Here we introduce a significant advancement that enables reflection interference contrast microscopy to provide nearly instantaneous reconstruction of an arbitrary convex object's contour next to a bounding surface with nanometre resolution, making it possible to interrogate microparticle/surface interaction phenomena at radii of curvature 1,000 times smaller than those accessible by the conventional surface force apparatus. The unique view-from-below perspective of reflection interference contrast microscopy also reveals previously unseen deformations and allows the first direct observation of femtolitre-scale capillary condensation dynamics underneath micron-sized particles. Our implementation of reflection interference contrast microscopy provides a generally applicable nanometre-scale resolution tool that can be potentially exploited to dynamically probe ensembles of objects near surfaces so that statistical/probabilistic behaviour can be realistically captured.

No MeSH data available.


Related in: MedlinePlus

Schematic of surface profile reconstruction.Interference fringe patterns obtained from RICM images embed precise information about an object’s topography in the vicinity of contact with a surface.
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f3: Schematic of surface profile reconstruction.Interference fringe patterns obtained from RICM images embed precise information about an object’s topography in the vicinity of contact with a surface.

Mentions: Although contact phenomena can be directly observed and quantified (typically as an area in the RICM image), accurate analysis of the interference pattern requires a link between the intensities and the object’s geometry (Fig. 3). Instead of applying the complete non-planar interface image formation theory, where all possible contributions to the observed intensity must be individually determined16, we consider a simplified two-dimensional model whereby a single set of complementary rays, I0, interfere to produce the intensity observed at a position x in the interferogram, I(x). For the single-layer system in Fig. 4a, I(x) depends on the interference of rays I1 and I2 in terms of their optical path length difference OPLD (term in square brackets) as follows.


A nanometre-scale resolution interference-based probe of interfacial phenomena between microscopic objects and surfaces.

Contreras-Naranjo JC, Ugaz VM - Nat Commun (2013)

Schematic of surface profile reconstruction.Interference fringe patterns obtained from RICM images embed precise information about an object’s topography in the vicinity of contact with a surface.
© Copyright Policy - open-access
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC3675327&req=5

f3: Schematic of surface profile reconstruction.Interference fringe patterns obtained from RICM images embed precise information about an object’s topography in the vicinity of contact with a surface.
Mentions: Although contact phenomena can be directly observed and quantified (typically as an area in the RICM image), accurate analysis of the interference pattern requires a link between the intensities and the object’s geometry (Fig. 3). Instead of applying the complete non-planar interface image formation theory, where all possible contributions to the observed intensity must be individually determined16, we consider a simplified two-dimensional model whereby a single set of complementary rays, I0, interfere to produce the intensity observed at a position x in the interferogram, I(x). For the single-layer system in Fig. 4a, I(x) depends on the interference of rays I1 and I2 in terms of their optical path length difference OPLD (term in square brackets) as follows.

Bottom Line: Interferometric techniques have proven useful to infer proximity and local surface profiles of microscopic objects near surfaces.But a critical trade-off emerges between accuracy and mathematical complexity when these methods are applied outside the vicinity of closest approach.Here we introduce a significant advancement that enables reflection interference contrast microscopy to provide nearly instantaneous reconstruction of an arbitrary convex object's contour next to a bounding surface with nanometre resolution, making it possible to interrogate microparticle/surface interaction phenomena at radii of curvature 1,000 times smaller than those accessible by the conventional surface force apparatus.

View Article: PubMed Central - PubMed

Affiliation: Artie McFerrin Department of Chemical Engineering, Texas A&M University, College Station, Texas, USA.

ABSTRACT
Interferometric techniques have proven useful to infer proximity and local surface profiles of microscopic objects near surfaces. But a critical trade-off emerges between accuracy and mathematical complexity when these methods are applied outside the vicinity of closest approach. Here we introduce a significant advancement that enables reflection interference contrast microscopy to provide nearly instantaneous reconstruction of an arbitrary convex object's contour next to a bounding surface with nanometre resolution, making it possible to interrogate microparticle/surface interaction phenomena at radii of curvature 1,000 times smaller than those accessible by the conventional surface force apparatus. The unique view-from-below perspective of reflection interference contrast microscopy also reveals previously unseen deformations and allows the first direct observation of femtolitre-scale capillary condensation dynamics underneath micron-sized particles. Our implementation of reflection interference contrast microscopy provides a generally applicable nanometre-scale resolution tool that can be potentially exploited to dynamically probe ensembles of objects near surfaces so that statistical/probabilistic behaviour can be realistically captured.

No MeSH data available.


Related in: MedlinePlus