Hybrid additive-subtractive laser fabrication platform for shaping hydrogels

Patent metadata

Field	Value
Publication number	US-11260596-B2
Application number	US-201916973235-A
Country	US
Kind code	B2
Filing date	Jul 11, 2019
Priority date	Jul 11, 2018
Publication date	Mar 1, 2022
Grant date	Mar 1, 2022

Abstract

A hybrid laser printing (HLP) technology that utilizes ultrafast laser in sequential additive-subtractive modes to create 3D hydrogel constructs. The approach involves the synergistic use of additive crosslinking and subtractive ablation processes that are conventionally mutually exclusive. HLP can be operated at virtually any penetration depth and allow fabrication of multi-layer hydrogel constructs at micrometer resolution. HLP was used to print ready-to-use functional chips using commonly used hydrogels for potential cellular communication and migration applications. HLP was also found to be compatible with in situ printing of cell-laden hydrogel constructs. HLP makes shaping of soft hydrogels into 3D multi scale functional devices possible.

First claim

What is claimed is:

1. A system for forming a structure from a hydrogel, comprising:
a stage having a sample holder for holding a hydrogel prepolymer solution and a window formed through the sample holder;
a femtosecond laser source capable of emitting a plurality of laser pulses having a first predetermined wavelength;
a second harmonic generator aligned with the femtosecond laser source to generate a second predetermined wavelength for a first portion of the plurality of the laser pulses;
a digital micro-mirror device aligned with the second harmonic generator and the window of the stage to spatially modulate ultraviolet wavelength pulses according to a first predetermined pattern so that the hydrogel prepolymer solution is cross-linked into a layer of a hydrogel polymer according to the first predetermined pattern; and
an objective lens aligned with the femtosecond laser source and the window of the stage to allow a second portion of the laser pulses having the first predetermined wavelength to ablate a plurality of voids in the layer of the hydrogel polymer.

2. The system of claim 1 , wherein the stage is configured to translate away from the window after the layer of the hydrogel polymer after the plurality of voids are ablated.

3. The system of claim 2 , wherein the first predetermined wavelength is 800 nm.

4. The system of claim 3 , wherein the second predetermined wavelength is 400 nm.

5. The system of claim 4 , wherein the layer of the hydrogel polymer is spaced apart from the window by a zone having a predetermined thickness and including the hydrogel prepolymer solution.

6. The system of claim 5 , wherein the plurality of voids are formed in an ablation range adjacent to the zone.

7. The system of claim 6 , wherein the hydrogel prepolymer solution comprises polyethylene glycol diacrylate.

8. The system of claim 7 , wherein each of the plurality of laser pulses are 150 femtoseconds wide.

9. The system of claim 7 , wherein the plurality of laser pulses have a repetition rate of 80 MHz.

Assignees

• Soman Pranav
• Kunwar Puskal
• Xiong Zheng
• Univ Syracuse

Inventors

• Soman Pranav
• Kunwar Puskal
• Xiong Zheng

Classifications

• G02F1/37 Primary

  for second-harmonic generation {(G02F1/3532 takes precedence)} · CPC title

• G02F1/372

  Means for homogenizing the output beam · CPC title

• B33Y30/00

  Apparatus for additive manufacturing; Details thereof or accessories therefor · CPC title

• B29C64/135

  the energy source being concentrated, e.g. scanning lasers or focused light sources · CPC title

• B29C64/277 Primary

  using multiple radiation means, e.g. micromirrors or multiple light-emitting diodes [LED] · CPC title