Photonics and Microfluidics

In Micronova the R&D of photonics and microfluidics includes the development of integrated optics, single mode waveguide optics, fiber optics (sensors), optoelectronic modules (integrated on Si), microfluidic chips (on silicon and glass), microfluidics instrumentation, lab-on-chip technology,  biosensors, fluorescence measurements and various combinations of these technologies. The main application areas are optical communication, medical diagnostics, environmental monitoring and on-line bio/chemical process analysis. The associated R&D work is very multidisciplinary and carried out with a global network of partners. In the Micronova clean-room facility the developed fabrication processes can be fluently scaled to production. The four most important key technologies are described in more detail below.

Photonic circuits on SOI

Photonic circuits on silicon-on-insulator have been continuously developed at VTT since 1997. Unlike most of the players in the global "Silicon photonics" R&D trend we have concentrated on 1–10 µm thick SOI rib waveguides that offer wider bandwidth, smaller polarisation sensitivity and smaller propagation and coupling losses than sub-µm SOI waveguides. Because of the unique sclability of the rib waveguide cross-section the optimum SOI thickness can be optimised for each application based on the requirements for optical I/O coupling (fibers, lasers etc.), polarisation dependency and footprint.


Integration and packaging of optoelectronics on silicon

In Micronova optoelectronic modules are assembled on both SOI and Si platforms using advanced integration and packaging technologies that are continuously developed to offer even better alignment accuracy, reliability and cost-efficiency. Optoelectronic chips, such as lasers, amplifiers, modulators and photodetectors are obtained from our partners and integrated together or into our SOI waveguide circuits. In 2011 VTT became one of the service providers for ePIXfab ( and now has the opportunity to offer integration and packaging solutions for the global user base of this multi-project wafer service in Si photonics.


Silicon/glass microfluidicsTA2.jpg

The micro-fabrication processes available in Micronova are used to implement microfluidics on glass and silicon chips. The mechanical ridigity, chemical resistance and low permeability properties of glass and silicon, as well as the optical transparency of glass make them best suited for life science and lab-on-chip applications. Examples of functions that have been demonstrated on the microfluidic chips are capillary electrophoresis, DNA amplification and cell stimulation. We have also developed unique multiport microneedle technology as well as a method to combine silicon/glass-based microfluidic functions with polymer based microfluidics.

Microfluidics instrumentation

VTT has over 10 year experience on microfluidics instrumentation needed in interfacing the silicon/glass microfluidics with off-chip fluidic devices (pumps, valves), electronics and optics to build microfluidic analysis systems for biochemical applications. We have developed precisely machined measurement platforms that have fluidic and electronic connections, easy replacement of the used microfluidic (silicon/glass/polymer) chip, open top surface for optical access, temperature control and automated LabView control for the external fluidic, electronic, optical and data logging devices.


Timo Aalto

Principal Scientist, Team Leader

Tel: +358 40 848 5037

E-mail: timo.aalto [at] vtt [dot] fi


For more information

VTT website: Micro and nanophotonics

VTT website: Biomicrosystems