A method for the characterization of the reflectance of anisotropic functional surfaces

The functional properties of micro-structured surfaces have gained increasing interest thanks to many applications such as wetting, adhesion, thermal and/or electrical conductivity. In this study, directional optical properties, i.e. contrast between two regions of a surface, were achieved with an anisotropic microstructure composed of a close array of ridges. The anisotropic surface, designed as a combination of ridges, has been milled on a steel bar and replicated through hot embossing of Acrylonitrile butadiene styrene (ABS) and through replica technology using silicone rubber. The directional reflectance of the surface for a range of design-specific view-illumination configurations was determined using a method that involves a Hirox RH-2000 digital microscope, used as a gonioreflectometer. This method allows the empirical determination of the optimum surface microstructure for maximizing contrast between two horizontally orthogonal views. The results show that even if the uncertainty related to the instrumentation is up to 20% in some cases, this procedure is suitable for the characterization of the surface of both metal and plastic counterpart.

[1]  Agostino G. Bruzzone,et al.  Functional Characterization of Structured Surfaces for Tribological Applications , 2013 .

[2]  Frédo Durand,et al.  Fabricating BRDFs at high spatial resolution using wave optics , 2013, ACM Trans. Graph..

[3]  Szymon Rusinkiewicz,et al.  A New Change of Variables for Efficient BRDF Representation , 1998, Rendering Techniques.

[4]  Xun Chen,et al.  Grinding for Microstructural Functional Surface , 2016 .

[5]  Akira Saito,et al.  Material design and structural color inspired by biomimetic approach , 2011, Science and technology of advanced materials.

[6]  Tim Weyrich,et al.  Fabricating microgeometry for custom surface reflectance , 2009, SIGGRAPH 2009.

[7]  Chaneel Park,et al.  Fabrication of micro-dimpled surfaces through micro ball end milling , 2013 .

[8]  Ulrike Schulz,et al.  Review of modern techniques to generate antireflective properties on thermoplastic polymers. , 2006, Applied optics.

[9]  W. Michaeli,et al.  Fast fabrication of super-hydrophobic surfaces on polypropylene by replication of short-pulse laser structured molds , 2010 .

[10]  Jannik Boll Nielsen,et al.  Process chain for fabrication of anisotropic optical functional surfaces on polymer components , 2017 .

[12]  Hans Nørgaard Hansen,et al.  Surface microstructure replication in injection molding , 2007 .

[13]  Prabitha Urwyler,et al.  Surface patterned polymer micro-cantilever arrays for sensing , 2011 .

[14]  Jitendra Malik,et al.  Recovering high dynamic range radiance maps from photographs , 1997, SIGGRAPH.

[15]  Jeffrey R. Alcock,et al.  Micro-injection moulding of polymer microfluidic devices , 2009 .

[16]  Mark A. Purnell,et al.  Accuracy and Precision of Silicon Based Impression Media for Quantitative Areal Texture Analysis , 2015, Scientific Reports.

[17]  R. Hocken,et al.  Replication of micro and nano surface geometries , 2011 .

[18]  M. J. Roberts,et al.  Engineering of Micro‐ and Nanostructured Surfaces with Anisotropic Geometries and Properties , 2012, Advanced materials.

[19]  Helmut Schift.  Nanoimprint lithography process chains for the fabrication of micro- and nanodevices , 2014, Advanced Lithography.

[20]  Agostino G. Bruzzone,et al.  Advances in engineered surfaces for functional performance , 2008 .