skip to main content
US FlagAn official website of the United States government
dot gov icon
Official websites use .gov
A .gov website belongs to an official government organization in the United States.
https lock icon
Secure .gov websites use HTTPS
A lock ( lock ) or https:// means you've safely connected to the .gov website. Share sensitive information only on official, secure websites.

Explore Research Products in the PAR
It may take a few hours for recently added research products to appear in PAR search results.


Title: Maximizing scanning speed in the ultrafast laser cutting of thin materials
A mathematical model is derived to predict the maximum speed of a focused laser beam in the laser cutting of thin materials. This model contains only two material parameters and is used to obtain an explicit relationship between the cutting speed and laser parameters. The model shows that there exists an optimal focal spot radius with which cutting speed is maximized for a given laser power. We compare the modeling results with experiments and find a good agreement after correcting laser fluence. This work is useful for the practical application of lasers in processing thin materials such as sheets and panels.  more » « less
Award ID(s):
1846671
PAR ID:
10399837
Author(s) / Creator(s):
;
Publisher / Repository:
Optical Society of America
Date Published:
Journal Name:
Optics Express
Volume:
31
Issue:
6
ISSN:
1094-4087; OPEXFF
Format(s):
Medium: X Size: Article No. 9750
Size(s):
Article No. 9750
Sponsoring Org:
National Science Foundation
More Like this
  1. ; ; (, Journal of Manufacturing Science and Engineering)
    null (Ed.)
    Abstract Origami-based fabrication strategies open the door for developing new manufacturing processes capable of producing complex three-dimensional (3D) geometries from two-dimensional (2D) sheets. Nevertheless, for these methods to translate into scalable manufacturing processes, rapid techniques for creating controlled folds are needed. In this work, we propose a new approach for controlled self-folding of shape memory polymer sheets based on direct laser rastering. We demonstrate that rapidly moving a CO2 laser over pre-strained polystyrene sheets results in creating controlled folds along the laser path. Laser interaction with the polymer induces localized heating above the glass transition temperature with a temperature gradient across the thickness of the thin sheets. This gradient of temperature results in a gradient of shrinkage owing to the viscoelastic relaxation of the polymer, favoring folding toward the hotter side (toward the laser source). We study the influence of laser power, rastering speed, fluence, and the number of passes on the fold angle. Moreover, we investigate process parameters that produce the highest quality folds with minimal undesired deformations. Our results show that we can create clean folds up to and exceeding 90 deg, which highlights the potential of our approach for creating lightweight 3D geometries with smooth surface finishes that are challenging to create using 3D printing methods. Hence, laser-induced self-folding of polymers is an inherently mass-customizable approach to manufacturing, especially when combined with cutting for integration of origami and kirigami. 
    more » « less
  2. (, Journal of Manufacturing and Materials Processing)
    This paper describes a sample partitioning approach to retain or reject samples from an initial distribution of stability maps using milling test results. The stability maps are calculated using distributions of uncertain modal parameters that represent the tool tip frequency response functions and cutting force model coefficients. Test points for sample partitioning are selected using either (1) the combination of spindle speed and mean axial depth from the available samples that provides the high material removal rate, or (2) a spindle speed based on the chatter frequency and mean axial depth at that spindle speed. The latter is selected when an unstable (chatter) result is obtained from a test. Because the stability model input parameters are also partitioned using the test results, their uncertainty is reduced using a limited number of tests and the milling stability model accuracy is increased. A case study is provided to evaluate the algorithm. 
    more » « less
  3. ; ; ; ; ; ; ; ; (, SPIE LASE, 2019, San Francisco, California, United States)
    The use of laser induced forward transfer (LIFT) techniques for printing materials for sensor and electronics applications is growing as additive manufacturing expands into the fabrication of functional structures. LIFT is capable of achieving high speed/throughput, high-resolution patterns of a wide range of materials over many types of substrates for applications in flexible-hybrid electronics. In many LIFT applications, the use of a sacrificial or laser-absorbing donor layer is required despite the fact that it can only be used once. This is because the various types of release layers commonly in use with LIFT are completely vaporized when illuminated with a laser pulse. A better solution would be to employ a reusable laser absorbing layer to which the transferable ink or material is attached and then released by a laser pulse without damage to the absorbing layer, therefore allowing its repeated use in subsequent transfers. In this work, we describe the use of two types of reusable laser-absorbing layers for LIFT. One is based on an elastomeric donor layer made from poly(dimethylsiloxane) or PDMS, while the other is based on a ceramic thin film comprised of indium tin oxide (ITO). These release layers have been used at NRL to transfer a wide range of materials including fluids, nanoinks, nanowires and metal foils of varying size and thickness. We will present examples of both PDMS and ITO as donor layers for LIFT and their reusability for laser printing of distinct materials ranging from fluids to solids. 
    more » « less
  4. ; ; (, ASME 2022 17th International Manufacturing Science and Engineering Conference)
    Abstract Lasers have a wide range of manufacturing applications, one of which is the bending of metals. While there are multiple ways to induce bending in metals with lasers, this paper examines laser peen forming with femtosecond lasers on thin metals of 75-micrometer thickness perpendicular to the laser. The effects of multiple parameters, including laser energy, scan speed, scan pitch, and material preparation, on the bend angle of the metal are investigated. The bend angles are generated in both concave and convex directions, represented by positive and negative angles, respectively. While it is possible to create angles ranging from 0 to 90 degrees in the concave direction, the largest average convex angle found was only −26.2 degrees. The positive angles were created by high overlapping ratios and slow speeds. Furthermore, the concave angles were made by a smaller range of values than the convex angles, although this range could be expanded by higher laser energy. The positive angles also had a higher inconsistency than the negative angles, with an average standard deviation of 6.8 degrees versus an average of 2.6 degrees, respectively. The characterization of bending angles will allow for more accurate predictions, which will benefit traditional metal forming applications and more advanced applications such as origami structures with metal. 
    more » « less
  5. ; ; ; ; ; ; ; ; ; ; et al (, Advanced Optical Materials)
    Abstract Over the past decades, optical manipulation of magnetization by ultrafast laser pulses has attracted extensive interest. It not only shows intriguing fundamental science arising from the interactions between spins, electrons, phonons, and photons, but also manifests the potential to process and store data at a speed that is three orders of magnitude faster than the current technologies. In this paper, all‐optical helicity‐dependent switching (AO‐HDS) in hybrid metal–ferromagnet thin films, which consist of Co/Pt multilayers with perpendicular magnetic anisotropy and an Au film capping layer on the top, is experimentally demonstrated. The switching behaviors of the hybrid Co/Pt–Au material, with various laser repetition rates, scanning speeds, and fluencies, are systematically studied. In comparison with bare Co/Pt multilayers, the hybrid metal–ferromagnet thin films show pronounced AO‐HDS when the number of laser pulses per μm along the scanning direction gradually increases. In addition, the AO‐HDS effect is very robust against laser fluences. A possible mechanism is further proposed based on numerical simulations of the optomagnetic coupling model. These findings promise a new material system that exhibits stable AO‐HDS phenomena, and hence can transform future magnetic storage devices, especially with the addition of plasmonic nanostructures made of noble metals. 
    more » « less
  • Citation Formats
  • MLA
  • APA
  • Chicago
  • BibTeX
  • Save / Share this Record
  • Send to Email