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ORIGINAL ARTICLE

Laser-induced Forward Transfer Hydrogel Printing: A

Defined Route for Highly Controlled Process

Vladimir Yusupov , Semyon Churbanov , Ekaterina Churbanova , Ksenia Bardakova ,
1
1,2
1,2
1
Artem Antoshin , Stanislav Evlashin , Peter Timashev 1,2,4,5 , Nikita Minaev 1*
3
1,2
1 Institute of Photon Technologies, Federal Scientific Research Centre “Crystallography and Photonics,” Russian Academy of
Sciences, Pionerskaya 2, Troitsk, Moscow, 108840, Russia
2 Institute for Regenerative Medicine, Sechenov First Moscow State Medical University, 8-2 Trubetskaya st., Moscow, 119991,
Russia
3 Center for Design Manufacturing and Materials, Skolkovo Institute of Science and Technology, Bolshoy Boulevard 30, Bld.
1, Moscow, 121205, Russia
4 Department of Polymers and Composites, N.N.Semenov Institute of Chemical Physics, 4 Kosygin St., Moscow, 119991,
Russia
5 Department of Chemistry, Lomonosov Moscow State University, Leninskiye Gory 1-3, Moscow 119991, Russia

Abstract: Laser-induced forward transfer is a versatile, non-contact, and nozzle-free printing technique which has demonstrated
high potential for different printing applications with high resolution. In this article, three most widely used hydrogels in bioprinting
(2% hyaluronic acid sodium salt, 1% methylcellulose, and 1% sodium alginate) were used to study laser printing processes. For
this purpose, the authors applied a laser system based on a pulsed infrared laser (1064 nm wavelength, 8 ns pulse duration, 1 – 5 J/
cm laser fluence, and 30 μm laser spot size). A high-speed shooting showed that the increase in fluence caused a sequential change
2
in the transfer regimes: No transfer regime, optimal jetting regime with a single droplet transfer, high speed regime, turbulent
regime, and plume regime. It was demonstrated that in the optimal jetting regime, which led to printing with single droplets, the
size and volume of droplets transferred to the acceptor slide increased almost linearly with the increase of laser fluence. It was
also shown that the maintenance of a stable temperature (±2°C) allowed for neglecting the temperature-induced viscosity change
of hydrogels. It was determined that under room conditions (20°C, humidity 50%), the hydrogel layer, due to drying processes,
decreased with a speed of about 8 μm/min, which could lead to a temporal variation of the transfer process parameters. The authors
developed a practical algorithm that allowed quick configuration of the laser printing process on an applied experimental setup.
The configuration is provided by the change of the easily tunable parameters: Laser pulse energy, laser spot size, the distance
between the donor ribbon and acceptor plate, as well as the thickness of the hydrogel layer on the donor ribbon slide.

Keywords: LIFT, Laser-induced forward transfer, Hydrogel parameters, Optimal jetting regime, Jet and droplets parameters

*Corresponding Author: Nikita Minaev, Institute of Photonic Technologies, Federal Scientific Research Centre “Crystallography and
Photonics,” Russian Academy of Sciences, Pionerskaya 2, Troitsk, Moscow, 108840, Russia; minaevn@gmail.com

Received: February 20, 2020; Accepted: March 16, 2020; Published Online: April 23, 2020
(This article belongs to the Special Section: Bioprinting in Russia)
Citation: Yusupov V, Churbanov S, Churbanova E, et al., 2020, Laser-induced Forward Transfer hydrogel printing: A defined
route for highly controlled process, Int J Bioprint, 6(3): 271. DOI: 10.18063/ijb.v6i3.271.

1 Introduction and background direct transfer of matter. This technology has been
used (1) to print a wide range of biological materials,
Laser-induced forward transfer (LIFT) is a digital such as proteins [1,2] and DNA [3,4] ; (2) to separate
printing technique that allows for the nozzle-free microorganisms ; (3) to print various types of cells
[5]
© 2020 Yusupov, et al. This is an Open Access article distributed under the terms of the Creative Commons Attribution-NonCommercial 4.0 International
License (http://creativecommons.org/licenses/by-nc/4.0/), permitting all non-commercial use, distribution, and reproduction in any medium, provided the
original work is properly cited.
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