Measurements forfemtosecond laser
micro-milling andfunctional texturing
Femtosecond laser is an ultra-short pulse duration laser. Until 2016, it was
not possible to integrate a femtosecond laser onto a 5 axis machine. The
Swiss group Georg Fischer first achieved this in 2016 thus becoming world
pioneers in this technology. This development ushered in a new range ofpossibilities for manufacturing processes.
With an ultra-short pulse duration laser there are 2 main advantages incomparison to conventional technologies and/or other lasers: (1) Burr-freemicro-milling. There are virtually no thermal effects over the part. The result
is a clean and sharp micro-milling, with very sharp edges and high quality
surface finishing. (2) Being a “cold laser” we can engrave over any material:
sapphires, plastic, glass, ceramics, aluminum, Steel, etc.

Microrelleus SL is a company
established in 1983. They
specialize in laser texturing services(functional and design), laser micro
milling and industrial engraving
for molds, tools and pieces. In 2016
Microrelleus SL became world
pioneers in using a femtosecondlaser machine in 5 axis to service
their customers. They also use
nanosecond lasers for machining
in 5 axis, milling machines anddie-sinking EDM. The project wasundertaken by Raul Garcia.

It is optimal technology to use on micro-milling and functional texturing. In
2016, when Microrelleus invested in a femtosecond laser machine with 5 axis,
the measurement requirements had changed. They needed a technology toanalyze and measure at the micro and nano-scale for functional texturing.
Everything needed to be performed quickly with high accuracy.

CASE STUDY MEASUREMENTS FOR FEMTOSECOND LASER MICRO-MILLING
AND FUNCTIONAL TEXTURING1

■ Measurements
LASER MICRO-MILLINGThis technology is optimal for manufacturing microcavities in mold,microfluidic channels, micro-milling for tempered steel tool or hard metal
tool, etc. Using Sensofar’s technology with the 5X and 20X objectives,
we were able to check each and every micro-milling project quickly andefficiently with easy to use and operate acquisition and analysis software.
Transparent materials such as glass or PMMA were imaged as well due
to Sensofar’s unique capability to combine Confocal and Focus Variation
techniques. This new technology is called Confocal Fusion and it merges
the information from both technologies into the same topography
without compromising acquisition time. Sensofar’s software algorithms
are optimized to choose the best acquisition data for each pixel. Thus, it ispossible to measure high slope angles with a low magnification objective
on highly reflective surfaces in confocal mode, which are common features
found on laser textured surfaces.

Figure [1]. Micro-milling over hard-metal tool and focus variation microscope analysis

FUNCTIONAL TEXTURING
Functional texture means adding functionality to the part because of
the micro or nano structures created over the material or over the moldof the plastic part. That functionality can be: super hydrophobicity,
superhydrophilicity, antibacterial, friction reduction, light diffraction, etc.
This is a new and complex process, and we have to be ensure the sizes are
perfect when we create the shape, both at the micro and nano scale.
Using Sensofar’s profiler in confocal mode with 100X magnification we areable to analyze nano structures over micro structures because of Sensofar’s
outstanding lateral resolution. That is something which we were not able toachieve using other manufacturer’s focus variation microscopes which is a
critical requirement for optimal texture functionality.

2CASE STUDY MEASUREMENTS FOR FEMTOSECOND LASER MICRO-MILLING
AND FUNCTIONAL TEXTURING

Figure [2]. Confocal microscope analysis of the micro and nano texture

created for superhydrophobic purposes

Figure [3]. Confocal microscope analysis of the nano texture

created for light diffraction purposes■ Conclusions
Sensofar’s confocal and focus variation technologies are an effective
combination of techniques to analyse micro-milling and functional texturing
over any material, both in the micro and nano scale. We are able to obtain
fast and non-destructive measurements to assure the following:1)

Micro-millings are delivered within the correct tolerance.

2)

Functional texturing will work properly based on the created texture.

CASE STUDY MEASUREMENTS FOR FEMTOSECOND LASER MICRO-MILLING
AND FUNCTIONAL TEXTURING

3

SENSOFAR is a leading-edge technology
company that has the highest quality standards
within the field of surface metrology
Sensofar Metrology provides high-accuracy optical profilers
based on confocal, interferometry and focus variation
techniques, from standard setups for R&D and quality
inspection laboratories to complete non-contact metrology
solutions for in-line production processes. The Sensofar Grouphas its headquarters in Barcelona, also known as a technology
and innovation hub in Europe. The Group is represented in over
30 countries through a global network of partners and has its own
offices in Asia, Germany and the United States.
HEADQUARTERS

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00CS-05B-EN-Microrelleus

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