As we enter into the 21st century, the need for miniaturized portable diagnostic devices is increasing continuously.
Portable devices find important applications for point-of-care diagnostics, patient self-monitoring and in remote
areas, such as unpopulated regions where the cost of large laboratory facilities is not justifiable, underdeveloped
countries and other remote locations such as space missions. The advantage of miniaturized sensing optical systems
includes not only the reduced weight and size but also reduced cost, decreased time to results and robustness (e.g. no
need for frequent re-alignments).
Recent advances in micro-fabrication and assembly technologies have enabled important developments in the field
of miniaturized sensing systems. INO has developed a technology platform for the three dimensional integration of
MOEMS on an optical microbench. Building blocks of the platform include microlenses, micromirrors, dichroic
beamsplitters, filters and optical fibers, which can be positioned using passive alignment structures to build the
desired miniaturised system. The technology involves standard microfabrication, thick resist UV-lithography, thick
metal electroplating, soldering, replication in sol-gel materials and flip-chip bonding processes. The technology is
compatible with wafer-to-wafer bonding. A placement accuracy of ± 5 μm has been demonstrated thanks to the
integration of alignment marks co registered with other optical elements fabricated on different wafers.
In this paper, the building blocks of the technology will be detailed. The design and fabrication of a 5x5 channels
light processing unit including optical fibers, mirrors and collimating microlenses will be described. Application of
the technology to various kinds of sensing devices will be discussed.