INTERNATIONAL JOURNAL OF PRECISION ENGINEERING AND MANUFACTURING Vol. 14, No. 9, pp. 1507-1512 SEPTEMBER 2013 / 1507
© KSPE and Springer 2013
Application of Image Processing to Micro-milling
Process for Surface Texturing
Hendra Prima Syahputra
1
and Tae Jo Ko
1,#
1 School of Mechanical Engineering, Yeungnam University, 214-1, Dae-dong, Gyeongsan-si, Gyeongsangbuk-do, South Korea, 712-749
# Corresponding Author / E-mail: tjko@yu.ac.kr, TEL: +82-53-810-3836, FAX: +82-53-810-4627
KEYWORDS: Image processing, Micro-milling, Surface texturing
Micro-milling is a well-known process for the micro-fabrication of miniature parts. Miniature parts are often used in the medical and
biology fields. In these fields, surface texture plays an important role in enhancing tactile qualities, aesthetics, and functionality. Most
of the surface textures in medical or biology applications are very complex and difficult to design on computer-aided design (CAD)
software. In this study, we develop a rapid process to acquire complex texture data by using an image processing technique. A complex
surface texture representing human skin is transferred to a metal surface. Several image processing step are used and pixel intensity
based height mapping for a two-dimensional (2-D) image to a three-dimensional (3-D) surface is described. The surface texture is
fabricated on aluminium using a micro-milling process. We describe a process in which polydimethylsiloxane (PDMS) is micro-
molded to the fabricated surface texture to produce an artificial skin.
Manuscript received: January 8, 2013 / Accepted: April 18, 2013
1. Introduction
Miniature parts are required in a wide range of critical applications
in the medical, aerospace, military and biology fields. Manufacturing
processes continuously evolve to meet the size requirements necessary
to produce miniature parts. In general, miniature parts ranging from a
few micrometers to tens of millimeters are needed. This has led to the
down-sizing of various conventional manufacturing processes into the
micro-scale range, such as micro-turning, micro-milling and micro-
molding. The development of micro-machining has been very rapid,
driven by the need for high-precision fabrications processes for
miniature parts. New types of actuators, sensors, and smart structures
are being developed to accelerate research in the micro-manufacturing
fields. New processes for micro-manufacturing have also emerged,
such as three-dimensional (3-D) printing, projection-based lithography
and laser machining.
The ability to produce miniature parts with smooth surfaces is not
enough in certain applications. Nowadays, surface textures must be
fabricated on miniature parts. Some initial work on a micro-milling
process for surface texturing was performed by Kobayashi and Shirai,
1
who fabricating a repetitive fabric pattern on a copper surface. Surface
texturing as a means of enhancing tribological properties of mechanical
components has been well known for many years. Micro-patterns and
micro-structures on flat or curved surfaces are attracting increasing
interest for research and industrial applications. There are many
interesting applications for micro/meso-scale textures.
Micro-structures (e.g., gratings) on optical surfaces change their
refractive and diffractive properties. Arrayed dimples on contact
surfaces under lubrication help to establish hydrodynamic pressure and
NOMENCLATURE
D = tool diameter (µm)
V = surface speed (m/min)
Π = 3.14159
N
s
= spindle speed (RPM)
f
m
= feedrate (mm/min)
ft = feed per tooth (mm)
n = number of flutes
X = length of 3-D surface data (Number of Pixel)
Y = width of 3-D surface data (Number of Pixel)
Z = height of 3-D surface data (Pixel Intensity)
l = length of workpiece (mm)
w = width of workpiece (mm)
h = height of workpiece (mm)
DOI: 10.1007/s12541-013-0203-y