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: Controlled Cell Alignment Using Two‐Photon Direct Laser Writing‐Patterned Hydrogels in 2D and 3D
Abstract Direct laser writing (DLW) via two‐photon polymerization is an emerging highly precise technique for the fabrication of intricate cellular scaffolds. Despite recent progress in using two‐photon‐polymerized scaffolds to probe fundamental cell behaviors, new methods to direct and modulate microscale cell alignment and selective cell adhesion using two‐photon‐polymerized microstructures are of keen interest. Here, a DLW‐fabricated 2D and 3D hydrogel microstructures, with alternating soft and stiff regions, for precisely controlled cell alignment are reported. The use of both cell‐adhesive and cell‐repellent hydrogels allows selective adhesion and alignment of human mesenchymal stem cells within the printed structure. Importantly, DLW patterning enables cell alignment on flat surfaces as well as irregular and curved 3D microstructures, which are otherwise challenging to pattern with cells.  more » « less
Award ID(s):
1647837
PAR ID:
10452323
Author(s) / Creator(s):
 ;  ;  ;  ;  
Publisher / Repository:
Wiley Blackwell (John Wiley & Sons)
Date Published:
Journal Name:
Macromolecular Bioscience
Volume:
21
Issue:
5
ISSN:
1616-5187
Format(s):
Medium: X
Sponsoring Org:
National Science Foundation
More Like this
  1. ; ; ; ; ; (, AIP Advances)
    We have quantified the adhesion forces between two-photon polymerization direct laser writing (TPP-DLW) microstructures and glass surfaces with and without an adhesion promoter. Glass surfaces treated with an acryloxy-silane agent produce adhesion forces that are almost three times larger than the forces observed with pristine glass surfaces. Determination of the substrates’ surface free energies suggests that the observed adhesion enhancement is chemical in its nature, implying that covalent bonds are formed between the polymer and the glass by means of the silane agent. The importance of this finding is demonstrated in the successful production of glassy carbon microstructures using TPP-DLW, followed by pyrolysis. 
    more » « less
  2. ; ; ; ; (, Advanced Materials Technologies)
    Abstract Direct laser writing (DLW) is an advanced fabrication technique that allows users to create complex 3D microstructures from polymer precursors. These microstructures can be integrated with micro‐electromechanical systems (MEMS) actuators. MEMS actuators provide a convenient platform for interacting with the intricate microstructures, either to characterize their mechanical properties or cause them to deform. Structures are fabricated directly onto electrostatic comb drives and chevron thermal actuators that are produced using a commercial foundry process. By applying a voltage to the MEMS actuators, highly controlled deformation of these microstructures is observed. Mechanical behaviors of microstructures produced with different materials and fabrication conditions are compared. MEMS–DLW integration is a convenient approach to characterizing the mechanics of DLW microstructures and may well lead to a new class of dynamic 3D devices for applications ranging from tissue engineering to imaging. 
    more » « less
  3. ; ; ; (, Lab on a Chip)
    Direct laser writing (DLW) is a three-dimensional (3D) manufacturing technology that offers vast architectural control at submicron scales, yet remains limited in cases that demand microstructures comprising more than one material. Here we present an accessible microfluidic multi-material DLW (μFMM-DLW) strategy that enables 3D nanostructured components to be printed with average material registration accuracies of 100 ± 70 nm (Δ X ) and 190 ± 170 nm (Δ Y ) – a significant improvement versus conventional multi-material DLW methods. Results for printing 3D microstructures with up to five materials suggest that μFMM-DLW can be utilized in applications that demand geometrically complex, multi-material microsystems, such as for photonics, meta-materials, and 3D cell biology. 
    more » « less
  4. ; ; ; ; ; ; ; ; (, Journal of Physics: Photonics)
    Abstract We demonstrate the use of tip-enhanced Raman spectroscopy (TERS) on polymeric microstructures fabricated by two-photon polymerization direct laser writing (TPP-DLW). Compared to the signal intensity obtained in confocal Raman microscopy, a linear enhancement of almost two times is measured when using TERS. Because the probing volume is much smaller in TERS than in confocal Raman microscopy, the effective signal enhancement is estimated to be ca. 104. We obtain chemical maps of TPP microstructures using TERS with relatively short acquisition times and with high spatial resolution as defined by the metallic tip apex radius of curvature. We take advantage of this high resolution to study the homogeneity of the polymer network in TPP microstructures printed in an acrylic-based resin. We find that the polymer degree of conversion varies by about 30% within a distance of only 100 nm. The combination of high resolution topographical and chemical data delivered by TERS provides an effective analytical tool for studying TPP-DLW materials in a non-destructive way. 
    more » « less
  5. ; ; ; ; ; ; (, 2021 IEEE 34th International Conference on Micro Electro Mechanical Systems (MEMS))
    null (Ed.)
    Additive manufacturing (or "three-dimensional (3D) printing") technologies offer unique means to expand the architectural versatility with which microfluidic systems can be designed and constructed. In particular, "direct laser writing (DLW)" supports submicron-scale 3D printing via two-photon (or multi-photon) polymerization; however, such high resolutions are poorly suited for fabricating the macro-to-micro interfaces (i.e., fluidic access ports) critical to microfluidic applications. To bypass this issue, here we present a novel strategy for using DLW to 3D print architecturally complex microfluidic structures directly onto-and notably, fully integrated with-macroscale fused silica tubes. Fabrication and experimental results for this "ex situ DLW (esDLW)" approach revealed effective structure-to-tube sealing, with fluidic integrity maintained during fluid transport from macroscale tubing, into and through demonstrative 3D printed microfluidic structures, and then out of designed outlets. These results suggest that the presented DLW-based printing approach for externally coupling microfluidic structures to macroscale fluidic systems holds promise for emerging applications spanning chemical, biomedical, and soft robotics fields. 
    more » « less
  • Citation Formats
  • MLA
  • APA
  • Chicago
  • BibTeX
  • Save / Share this Record
  • Send to Email