JLA Vol:24 Iss:4 (Direct laser writing-mediated generation of standardized topographies for dental implant surface optimization)

Authors:
Rainer Wittig
Institut fu¨r Lasertechnologien in der Medizin und Messtechnik (ILM) an der Universita¨t Ulm, 89081 Ulm, Germany

Erik Waller
Georg von Freymann
Arbeitsgruppe Optische Technologien und Photonik und Forschungszentrum OPTIMAS, Fachbereich Physik, Technische Universita¨t Kaiserslautern, 67663 Kaiserslautern, Germany

Rudolf Steiner
Institut fu¨r Lasertechnologien in der Medizin und Messtechnik (ILM) an der Universita¨t Ulm, 89081 Ulm, Germany

The functionalization of dental implants, aiming at the improvement of long-term acceptance, is of pivotal interest in dental research. Bone, connectiv...

JLA Vol:24 Iss:4 (Synthesis of hybrid microgels by coupling of laser ablation and polymerization in aqueous medium)

Authors:
Philipp Nachev
Funktionale und Interaktive Polymere, Institut fu¨r Makromolekulare und Technische Chemie, RWTH Aachen University, Forckenbeckstr. 50, D-52074 Aachen, Germany

Danielle D. van ’T Zand
Technical Chemistry I and Center for Nanointegration Duisburg-Essen (CeNIDE), University of Duisburg-Essen, Universitaetsstr. 5-7, D-45141 Essen, Germany

Vincent Coger
Department of Plastic, Hand- and Reconstructive Surgery, Hannover Medical School, Carl-Neuberg-Str. 1, 30625 Hannover, Germany

Philipp Wagener
Technical Chemistry I and Center for Nanointegration Duisburg-Essen (CeNIDE), University of Duisburg-Essen, Universit...

JLA Vol:24 Iss:4 (Nano structures via laser interference patterning for guided cell growth of neuronal cells)

Authors:
Elke A. Bremus-Koebberling
Stefan Beckemper
Fraunhofer Institute for Lasertechnology, Steinbachstr. 15, 52074 Aachen, Germany

Beate Koch


Arnold Gillner
Fraunhofer Institute for Lasertechnology, Steinbachstr. 15, 52074 Aachen, Germany and Chair for Laser Technology, Technical University Aachen, Germany

Laser interference patterning is a versatile tool for the fabrication of nano patterns. For this study, regular nano line patterns with feature sizes between 100 and 1000 nm were produced on polymers polyimide, polyetheretherketone, and polydimethylsiloxane. Cell culture experiments with B35 neuronal cells revealed the al...

JLA Vol:24 Iss:4 (Materials and technologies for fabrication of three-dimensional microstructures with sub-100 nm feature sizes by two-photon polymerization)

Authors:
Frank Burmeister
Institute of Applied Physics, Friedrich-Schiller-Universita¨t Jena, D-07743 Jena, Germany and Fraunhofer Institute for Applied Optics and Precision Engineering IOF, D-07745 Jena, Germany

So¨nke Steenhusen
Ruth Houbertz
Fraunhofer Institute for Silicate Research ISC, D-97082 Wu¨rzburg, Germany

Uwe D. Zeitner
Stefan Nolte
Andreas Tu¨nnermann
Institute of Applied Physics, Friedrich-Schiller-Universita¨t Jena, D-07743 Jena, Germany and Fraunhofer Institute for Applied Optics and Precision Engineering IOF, D-07745 Jena, Germany

The fabrication of sub-100 nm featu...

JLA Vol:9 Iss:1 (Laser generated air contaminants released during laser cutting of fabrics and polymers)

Authors:
Max Kiefer
C. Eugene Moss
National Institute for Occupational Safety and Health, Centers for Disease Control and Prevention, Cincinnati, OH 45226, U.S.A.

Environmental monitoring was conducted at an industrial facility to qualitatively identify the major contaminants generated while cutting fabrics and polymers with a 25 W CO₂ continuous beam laser. Carbon monoxide, hydrogen cyanide, and particulates were also assessed, and a bulk sample of residue from the laser exhaust duct was analyzed for inorganic acids, pH, and volatile organic compounds. Samples were collected while cutting vinyl, acrylics, woven fabrics, felt, Formica®, and Plexiglass®....

JLA Vol:9 Iss:1 (Continuous wave Nd:YAG laser cladding modeling: A physical study of track creation during low power processing)

Authors:
J‐.M. Jouvard
D. F. Grevey
F. Lemoine
A. B. Vannes

This paper concerns the modeling of cladding using an Nd:YAG laser operating at low powers typically less than 800 W. Experimental observation of the evolution of the mass of the clads shows two power thresholds. The theoretical study relies on a calculation of the fluence provided to the substrate and on a model of heat transfer into the substrate. We suggest that the first threshold is the power required for substrate melting. The second power is the threshold when the powder is directly melted by the beam and is therefore a liquid when contacting the substrate.

JLA Vol:9 Iss:1 (The development of a laser machining curriculum: An interdisciplinary approach (the MAST program))

Authors:
Gary J. Masciadrelli
Nicholas M. Massa

The development of an industry‐driven interdisciplinary curriculum in laser machining is presented. The Machine tool Advance Skills Technology (MAST) program is a US Department of Education grant to develop and demonstrate a national training model for new technologies and manufacturing processes in precision manufacturing. Springfield Technical Community College (STCC) in partnership with six other community colleges nationwide, developed, tested, and disseminated industry‐specific skills standards and model curricula in laser machining and related technologies for the United States machine tool industry. STC...

JLA Vol:9 Iss:1 (Laser cladding of Al‐Sn alloy on a mild steel)

Authors:
Z. Liu
J. L. Sun
W. M. Steen
K. G. Watkins
C. Lee
W. P. Brown

Direct laser cladding of Al alloy on mild steel produces continuous brittle intermetallic Fe_xAl_y layers at the interface resulting in weak bonding of the clad and the substrate. To overcome this problem, both Ni and Al were investigated as intermediate coatings. Although a Ni coating with a thickness of 70 μm was successful in eliminating the formation of continuous Al‐Fe intermetallics, the bonding at the Al alloy/Ni interface was not strong enough to survive a bending test. A pure Al coating was found to be a better ...

JLA Vol:9 Iss:2 (Kinematic compensation of repetitive errors for non‐circular laser shaping)

Authors:
P. Sheng
K. Liu
Department of Mechanical Engineering, University of California, Berkeley, CA, U.S.A.

This paper presents an approach for kinematic compensation of the laser shaping process which is capable of achieving improved dimensional accuracy for non‐circular profiles. In this approach, a plug‐in repetitive controller is added into the existing position servo loop to improve tracking of the desired sinusoidal trajectory and subsequently reduce tracking errors. The effect of tracking errors on different dimensional error modes in the non‐circular shaping process is identified. Simulation models are developed for testing the performance o...

JLA Vol:9 Iss:2 (Laser cladding with a pulsed Nd:YAG laser and optical fibers)

Authors:
M. Brandt
D. A. Scott
S. B. Emms
J. M. Yellup

A new laser cladding technique for producing wear and corrosion resistant surfaces on engineering components is reported. The technique involves the combination of the pre‐placed and injected powder delivery methods for producing clad layers. The clad layers were formed with a pulsed Nd:YAG laser and optical fibers. The results using a nickel‐based alloy (Hastelloy C) indicate that uniform clad layers in excess of 1 mm in thickness can be achieved in a single pass with 240 W average power incident on the workpiece. The laser beam was delivered through a step‐index glass ...