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Direct laser lithography or direct laser writing using two-photon deep ultraviolet laser for additive 3d manufacturing using conventional resin sensitive to two-photon absorption resulting in two-photon polymerization to create volumetric prints from CAD models.
Exposure System
The NanoScribe GT2 Laser Lithography System is an ultramodern two-photon polymerization volumetric maskless printer. It is one of our newest acquisitions here at the Cornell NanoScale Facility (CNF). The tool was purchased in late 2019 and delivered and installed during the second week of January 2020. This was accomplished with the help of a committee of faculty and researchers, and a grant from the NSF. The NanoScribe GT2 can create three-dimensional nanostructures using a NIR femtosecond laser via direct-write onto a photosensitive resin, which is subjected to a non-linear two-photon absorption process. This process involves cross-linking the resin via UV absorption. The laser sets a focal light cone where a concentration of the light intensity defines the exposure focal spot volume or a “3D Pixel.” Using this technique, a CAD design can be broken into an X-Y-Z coordinate system to define the structure pixel by pixel and layer by layer. The exposure side of the system sits in a fine-tuned vibration isolation table and a high-speed ultra-precise piezoelectric stage for movement in X-Y-Z and uses a galvanic mirror defection system for focusing and beam rasterization. Models for printing can be designed using the stand-alone software DeScribe—which comes with the tool—or with any CAD software capable of outputting file formats DXF or STL. The DeScribe software can import these formats.
3D Print Technology & Direct wright
Laser-based direct writing has been around for a few years especially in the semiconductor industry know known as maskless lithography (MPL). Typically, the two-dimensional CAD design is transferred onto the substrate that is pre-coated with a photosensitive resin via reduction laser projection. The projected pattern was reduced given the tool's numerical aperture and scan across the surface of the substrate using either a raster or vector format. These techniques are the same ones utilized in 3D direct-write. The only difference is that know you are working with a thickness degree of freedom that can be scanned across the Z-axis. The NanoScribe GT2 has a Piezo Nanopositioning stage and a high-speed galvo scanner. In the case of two-photon lithography, the light source is a pulsed femtosecond fiber laser with the center wavelength being around 780 nm.
Hardware Overview
Diagram of a simplified optical path of a Two-Photon Lithography System.
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- Send the tool manager a request for online access to NanoScribe’s NanoGuide Web-pageWebpage.
- Users are required and responsible for reviewing the services and procedures provided by NanoScribe on the following: [You will need to log in to NanoGuide to view these materials.]
- Import a CAD model File
- Prepare a sample & change the objective
- The end-user is responsible for maintaining their own supply of substrates.
- CNF will provide at no extra charge standard resist.
- Standard resins are:
- IP-Dip
- IP-S
- IP-L
- IP-Q
- Start NanoWrite and Insert sample holder
Perform a sample approach
Load a print Job
Print your structure
Unload the sample
Develop the sample
Clean the objective lens
Leaving the printer
3D Printer
- Overview and Safety
- Software (Software Overview, DeScribe, NanoWrite, Zeiss Axion Vision)
- Sample Holders
- Print Sets
- Hardware
- Objectives (Objective Overview, 63x, 25x, 10x)
- Substrates
- Cleaning and Maintenace
- Process Materials
- Printing Processes
- Model Creation and Import
- Print with Solution Sets
- Print Strategies
- Programming Structures
- Post Print Processes
- (Optional) Learning
- (For additional remote and e-learning from NanoScribe)
- Check your STL model for common mesh errors. You can use a cad use CAD software capable of mesh verification such as Autodesk Meshmixer or MeshLab
- Once your file has been checked for mesh errors, run it through DeScribe to do the conversion. Be sure to select the desired solution set (SF, MF, or LF) for your process.
- Sign up in CULearn for training:
- RSRCH - CNF - NanoScribe GT2 (NetID Link)
- RSRCH - CNF - NanoScribe GT2 (GuestID Link)
- Once you have watched the online CULearn training video send an email to the tool manager to arrange hands-on training.
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