The LIFT method can be used whenever tiny amounts of material need to be applied onto receiver substrates with pinpoint precision. One broad field of application for the technology is medical and pharmaceutical research, for instance, where diseases and active pharmaceutical ingredients are studied in specially made test structures. Here it is imperative to apply the precious material selectively and as sparingly as possible onto a receiver substrate. The LIFT method facilitates the transfer of a broad range of materials, such as glycoproteins, living cells, and metals – with high precision and using up a minimum of resources. The Biofabrication Group at Fraunhofer ILT is currently working on further developing complex cell-based in vitro test systems.
Transferring material without a printer head: cost-effective and reliable
This is how the printing process works: the receiver substrate is situated beneath a glass slide bearing the biomaterial to be transferred on its underside and an intermediate titanium absorber layer. A pulsed laser beam evaporates the titanium layer, and the resulting forwards impulse transfers the biomaterial onto the receiver substrate. This laser-based process has no need of a printer head and so it can transfer biomaterials such as RNA, DNA, proteins, and cells regardless of their viscosity. The absence of a printer head also means there is none of the associated sample wastage caused, for example, by feeder lines. This dramatically reduces the amount of material required to carry out an analysis. What is more, the LIFT method can produce spot sizes of 10 µm to 300 µm – which means up to 500,000 protein spots can fit onto a surface the size of a thumbnail. Until now it has not been possible to build up sample material with such precision and efficiency and in such small amounts.
From laboratory setups to a user-friendly machine
Fraunhofer ILT’s system development resulted in an innovative five-axis machine with motion systems for transfer and receiver substrates. The built-in beam source can be set to the wavelengths 355 nm or 1064 nm, and the focal position, laser power, and number of pulses can be automatically controlled. This enables the user to transfer a wide range of substances, from biomaterials to metals, with the LIFTSYS machine.
Researchers from the Process Control and System Technology Group in Aachen further developed the initial laboratory setups into the LIFTSYS machine. A main focus of their work was to ensure that the prototype was intuitive to operate. To this end, they integrated PC-based visualization and control technology into the system. There are two easy operating concepts for users to choose from: one is a graphical user interface, from which all elements of the system can be easily controlled; and the other is text-based programming in G-code. In addition to positioning commands, this text language also contains add-ons for laser processing: for example, laser pulses can be triggered individually and pulse energies changed. This makes it possible to program complex transfer patterns and assign them to a specific processing result.
Applications at EPFL in Lausanne
The Swiss Federal Institute of Technology in Lausanne EPFL is performing research in inkjet printing for various applications in micro-engineering, material science and bio-engineering. “The new LIFT method is a very interesting alternative to conventional nozzle-based inkjet printing, as new classes of materials can be locally deposited with low material waste,” explains Prof. Juergen Brugger of the EPFL. “The fact that even very high viscous liquids and solid films can be locally transferred to a receiver substrate makes the technique very versatile for several of our research groups.” The scientists at EPFL will first perform basic research to study the morphology and materials properties of the deposited pattern and will then benchmark the LIFT method with conventional inkjet printing. Subsequently, research for selected applications in the fields of semiconductors, biomaterials or sensors will be addressed. EPFL will also allow students to work on the new LIFT tool, preparing thus future engineers and scientists to be familiar with innovative surface patterning methods to enable novel manufacturing schemes and ultimately new applications.
LIFTSYS at Biotechnica 2013
At this year’s Biotechnica – Europe’s no.1 event for biotechnology, life sciences, and lab technology, which will take place in Hannover, Germany, from October 8 to 10, 2013 – Fraunhofer ILT will be presenting its LIFTSYS machine for the application field of in vitro test systems. At the joint Fraunhofer booth in Hall 9.E09, experts will be demonstrating a prototype machine along with other exhibits from the field of biofabrication.
Dr. Martin Wehner
Head Biotechnology and Laser Therapy Group
Telefon: +49 241 8906-202