2025-05-05 to 2025-05-23: Semi-Annual Facility Preventive Maintenance

Refer to the Material and Process Compatibility page for information on materials compatible with this tool.
Equipment Status: Set as UP, PROBLEM, or DOWN, and report the issue date (MM/DD) and a brief description. Italicized fields will be filled in by BNC Staff in response to issues. See Problem Reporting Guide for more info.

Status	UP
Issue Date and Description
Estimated Fix Date and Comment
Responding Staff

iLab Name	Nanoscribe Photonic Professional GT2 3D Printer
iLab Kiosk	BRK Lithography Core
FIC	David Cappelleri
Owner	Mihailo Bradash & Bill Rowe
Location	BRK 2100F
Max. Wafer	4"/100 mm
Info Links	/wiki/spaces/BNCWiki/pages/6250782\| /wiki/spaces/BNCWiki/pages/6248406

Overview

General Description

The Nanoscribe Photonic Professional GT2 uses Two-Photon Polymerization (2PP) to produce filigree structures of nearly any 3D shape by high-precision 3D printing: crystal lattices, porous scaffolds, naturally inspired patterns, smooth contours, sharp edges, undercuts and bridges are all manufacturable with high resolution. The printer is capable of printing in Mesoscale, and all the way down to Nanoscale, and is designed around work in Microfluidics, Micromechanics, Micro optics, Photonics and plasmonics, Biomedical applications, and Nanostructures.

Specifications

Machine specifications:


Printing technology	Layer-by-layer Two-Photon Polymerization
Minimum XY feature size	160 nm typical; 200 nm specified*
Finest XY resolution	400 nm typical; 500 nm specified*
Finest vertical resolution	1,000 nm typical; 1,500 nm specified*
Layer distance	Variable, 0.1 – 5.0 µm*
Maximum object height	8 mm*
Build volume	100 × 100 × 8 mm³ *
Minimum surface roughness Ra	≤ 20 nm*
Max. scan speed	From 100 to 625 mm/s*

*Values may vary depending on the Solution Set, objective or resin in use

Available resins:

2PP resin	Refractive index	Phase	Characteristics	Recommended Objective	Recommended substrate
IP-Dip	1.521	Liquid	high resolution	63x	Fused silica, Silicon, other substrates
IP-Dip2	1.526	Liquid	high resolution	63x	Fused silica, Silicon, other substrates
IP-L	1.485	Liquid	high resolution	63x	Fused silica, Silicon, other substrates
IP-G	1.495	Gel	high resolution; flying features	63x	Borosilicate, other substrates
IP-S	1.486	Liquid	high smoothness; meso-scale	25x	ITO-coated, Silicon, other substrates
IP-Q	1.487	Liquid	meso-scale	10x	Silicon
IP-Visio	1.486	Liquid	low fluorescence; non-cytotoxic	25x	ITO-coated, Superfrost
IP-PDMS	1.43	Liquid	highly flexible and elastic; non-cytotoxic; low refractive index	25x	ITO-coated, Superfrost
GP-Silica	1.463	Liquid	fused silica glass as final part; thermal, mechanical and chemical stability; high optical transparency	10x	Silicon, other substrates

Technology Overview

Click here to expand...

3D Printing using Two Photon Polymerization (2PP)

Nanoscribe's technology for the fabrication of three-dimensional micro- and nanostructures in photo-sensitive materials is based on direct laser writing (DLW): a non-linear two-photon absorption process (2PA; Figure 1). A necessary condition for two photons of near-infrared light being absorbed simultaneously is a sufficiently high light intensity that is provided by a femtosecond pulsed laser beam.[ref][ref] Typically, the laser is focused into the resin and two-photon polymerization (2PP) is triggered only in the focal spot volume (Figure 2-1), where the light intensity exceeds a polymerization threshold.[ref] The resin is otherwise transparent to the wavelength of the photons (Figure 2-2). In contrast, one photon absorption (1PA) with an equivalent energy takes place along the whole light cone (Figure 2-2).
The smallest printable 3D volume is termed a voxel, which is analogous to a 2D pixel. Moving the laser focus along a trajectory in all three dimensions enables printing of structures built from multiple voxels and printed lines (Figure 3). This technology enables printing of structures with small, medium and large feature sizes in 3D as well as 2D patterns ( | ).

One and two photon absorption, where an excited state S₁ is reached that triggers polymerization of a suitable resin.

Representation of the intensity distribution for one and two photon absorption.

Imaging fluorescence from one and two photon absorption processes.

Comparison between one and two photon absorption (courtesy of S. Ruzin and H. Aaron, UC Berkeley).

Printing process of a 3D free-form structure using 2PP.[ref] The laser focus is deflected to precise locations in the resin as per the structural design. Development of the structure removes unpolymerized resin and the desired structure remains attached to the substrate.

The nonlinear light absorption of the 2PP resin exhibits an absorption probability $P_{m a t e r i a l} \propto L P_{a v g}^{n} \cdot t$ with $n$ reflecting the multi-photon process (mainly two photon activation), $t$ the time of exposure and $L P_{a v g}$ the average laser power.[ref] The absorption competes with a quenching process, leading to a threshold at which polymerization of the 2PP resin starts (Figure 4-1).[ref] The iso-intensity surface (Figure 4-2) in the focal spot where the intensity is equal to the threshold defines the size and shape of the printed ellipsoidal voxel.[ref] Figure 4-2 provides a plot of the squared intensities $I^{2}$ , as this is proportional to the absorption probability for two photon absorption, $P_{m a t e r i a l} \propto I^{2}$ . In contrast, the one photon absorption probability is proportional to the intensity $I$ .[ref][ref]

3D squared-intensity spacial distribution and threshold for 2PP.[ref][ref]

2D squared-intensity spacial distribution for 2PP.

3D and 2D spacial distribution of intensity and polymerization threshold.

Structural dimensions

It is possible to print line widths smaller than the diffraction-limited resolution of the objective lens.[ref] However, the period of the lines still is diffraction-limited by the objective lens.[ref] In addition, the proximity effect of the polymerization limits the line printing period.[ref] The proximity effect describes the (in this case) unintended, sub-threshold polymerization of resin between neighboring printed lines. Adjusting the dose in the focal spot leads to variable voxel sizes, with a lower limit of polymerization theshold and an upper limit of over-exposure. The dose and the distance between neighboring printed lines control the degree of polymerization.

Sample Requirements and Preparation

Standard Operating Procedure

Training video on 6/24/2021, (only available for Purdue users)

Questions & Troubleshooting

Process Library

References
Nanoguide Wiki: https://support.nanoscribe.com/hc/en-gb
General user login:
UN: bncstud@purdue.edu
PW: BStud4*

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