Combination of additive and subtractive laser 3D microprocessing for lab-on-chip and chemical sensing applications

BACKGROUND

Recently, lab-on-chip devices proved to be highly functional, integrable and widely applicable. To make them more affordable to the end-users, the price of such chips must be lower. To achieve that, more simple technologies have to be used in their production, to reduce production costs. Preferably, contemporary lab-on-chip devices should also use little energy or be passive if possible.

TECHNOLOGY

We propose a technology that combines additive and subtractive laser 3Dmicroprocessing in hybrid glass/polymer microsystems, using single femtosecond laser source. The methods are simple and easily applicable:

1) Passive particle separator for microfluidics. First, laser ablation is used to produce microfluidic channels in the glass substrates. Then, 3D laser lithography is employed to integrate microfilters, made from hybrid organic–inorganic photopolymer SZ2080, into the channels. Finally, the chip is sealed with a glass cover by laser welding. All the steps are performed using anYb:KGW femtosecond laser source. The integrated filters can sort microparticles (from 1 to 10μm diameter) in water [1].

2) Passive micromechanical sensor. Laser-assisted etching is used to fabricate 3D microstructure (cantilevers) in glass. Then, via the two photon polymerization technique, a polymeric beam, made from hybrid organic–inorganic photopolymer SZ2080, is integrated between the cantilever and the fixed glass base. Polymeric beam swells or shrinks when immersed in different liquids, causing the cantilever to bend upwards or downwards. Thus cantilever acts as an amplification system and tester for investigating the elastic properties of the polymeric beam or can be used as a sensor for specific liquids [2].

BENEFITS

• Simple, versatile and easily applicable method of manufacturing.
• Additive and subtractive processing is done by the same single laser source, so separate fabrication steps can be integrated into one manufacturing system.
• Made from easily accessible materials – glass and photopolymer SZ2080.
• Filter meshes can be customized according to the needs.
• Particle separator and micromechanical sensor are passive, i.e. do not need external source of energy to operate.

APPLICATION

The present technology can be used in various applications:

• Lab-on-chip devices;
• Microfluidic devices for cell sorting, counting, liquid mixing and filtering;
• Biomedicine;
• Micro-optics;
• Investigation of properties of new polymeric materials and micro-elements;
• Investigation of chemical properties of liquids.

INTELLECTUAL PROPERTY

Authors: L.Jonušauskas, S. Rekštytė, R.Buividas, S. Butkus, R.Gadonas, S.Juodkazis, M. Malinauskas, T.Tičkūnas, D. Paipulas, Y.Bellouard, V. Sirutkaitis.

PUBLICATIONS

[1] L.Jonušauskas, S.Rekštytė, R.Buividas, S. Butkus, R.Gadonas, et al.Hybrid subtractive-additive-welding microfabrication for lab-on-chip applications viasingle amplified femtosecond laser source.Opt.Eng. 56(9) 094108 (2017).https://doi.org/10.1117/1.OE.56.9.094108

[2] T.Tičkūnas, M.Perrenoud, S. Butkus, R.Gadonas, S.Rekštytė, et al.Combination of additive and subtractive laser 3Dmicroprocessing in hybrid glass/polymer microsystems for chemical sensing applications.Opt. Express 25, 26280-26288 (2017).https://doi.org/10.1364/OE.25.026280

Current development status

Others

TRL 3 – experimental proof-of-concept demonstrated.