Evolution of Shock-Induced Pressure in Laser Bioprinting

Evgenii Mareev,Nikita Minaev,Vladimir Yusupov,Vyacheslav Zhigarkov

doi:10.3390/photonics8090374

Abstract

Laser bioprinting with gel microdroplets that contain living cells is a promising method for use in microbiology, biotechnology, and medicine. Laser engineering of microbial systems (LEMS) technology by laser-induced forward transfer (LIFT) is highly effective in isolating difficult-to-cultivate and uncultured microorganisms, which are essential for modern bioscience. In LEMS the transfer of a microdroplet of a gel substrate containing living cell occurs due to the rapid heating under the tight focusing of a nanosecond infrared laser pulse onto thin metal film with the substrate layer. During laser transfer, living organisms are affected by temperature and pressure jumps, high dynamic loads, and several others. The study of these factors’ role is important both for improving laser printing technology itself and from a purely theoretical point of view in relation to understanding the mechanisms of LEMS action. This article presents the results of an experimental study of bubbles, gel jets, and shock waves arising in liquid media during nanosecond laser heating of a Ti film obtained using time-resolving shadow microscopy. Estimates of the pressure jumps experienced by microorganisms in the process of laser transfer are performed: in the operating range of laser energies for bioprinting LEMS technology, pressure jumps near the absorbing film of the donor plate is about 30 MPa. The efficiency of laser pulse energy conversion to mechanical post-effects is about 10%. The estimates obtained are of great importance for microbiology, biotechnology, and medicine, particularly for improving the technologies related to laser bioprinting and the laser engineering of microbial systems.

Highlights

Laser-induced forward transfer (LIFT) is based on the transfer of a microscopic amount of matter because of laser pulsed heating
The purpose of this article was to study the parameters of dynamic processes in bioprinting and laser engineering of microbial systems (LEMS) technologies, and to estimate the pressure jumps that occur in a liquid layer near an absorbing film during laser printing using time-resolved shadow microscope photography
We presented the experimental results of the study parameters of the process formation of bubbles and jets of gel during laser printing by gel microdroplets upon absorption of a laser pulse with λ = 1053 nm and τ = 8 ns in a thin Ti layer of a donor plate

Summary

Introduction

Laser-induced forward transfer (LIFT) is based on the transfer of a microscopic amount of matter because of laser pulsed heating. It is a promising alternative to traditional printing methods [1]. Laser printing technologies are actively used in various fields, such as medicine and biotechnology, for printing with cell and microbial cultures to create artificial tissue-engineered and cell-engineered structures [2]. In these cases, the term laser bioprinting is widely used [3]. A promising modification of the laser printing method is laser engineering of microbial systems (LEMS) technology. It has already been proven that LEMS will make it possible to separate symbionts [4] and isolate individual microorganisms that are difficult to cultivate or not cultivated at all by standard methods [5,6,7]. It is important that this process is necessary for solving the urgent problem of creating the demanded “Noah’s Ark”—the World Bank of Microorganisms [8]—and for the production of biologically active substances [9] and the synthesis of new antibiotics [10]

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