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Berlin University of Technology,
Microsensor and Actuator
Technology Center (TUB)
 The
Microsensor & Actuator Technology Center (MAT) is
part of the research unit "Microperipheric Technologies"
of Berlin University of Technology (TUB) and
has been founded in 1987. The MAT is one of the leading
MEMS development centres in Germany, employing more
than 20 research scientists. Numerous MEMS devices or
processes have been developed by MAT/TUB, usually in
collaboration with industrial partners as for example
Siemens, EADS ,and Schlumberger. The MAT has been involved
in many national (BMBF, DFG) and European projects (EU:
TECSICA, SICOIN). The research of MAT has focused on
the development and realization of silicon based MEMS
actuators like micro relays, micro mirrors and thermal
ink-jet heads. Further, new MEMS processes and materials
are investigated and micro sensors are developed. Modern
computer aided design methods (like FEA with ANSYS 7)
are used to optimize the characteristics of actuators
and sensors. The in-house labs and clean room facility
include equipment for standard CMOS processes for oxidation,
annealing, sputtering of complex multilevel metallization
schemes, photolithography, wet and dry etching together
with silicon micromachining techniques. Special processes
as anisotropic etching, electrochemical etching, anodic
bonding and fusion bonding are also available.
The MAT has published pioneering work covering nearly
the whole field of MEMS technology and has a high expertise
in the area of MEMS process technology, micro sensors
and micro actuators. During the last 15 years special
processes for MEMS fabrication have been investigated
in scientific manner and have been optimized. Anisotropic
silicon etching using KOH is cheap and, besides DRIE,
the technology of choice for deep etching of silicon
and for bulk micromachining. The KOH etching process
has been continuously developed further and is one of
the most reliable MEMS processes. Bonding techniques
like fusion bonding and anodic bonding, allow a durable
and sealed bond between Si and Si or between Si and
borosilicate glass. KOH etching can be used for etching
of channel structures and fuel reservoirs of the novel
micro fuel injector, while the mentioned bonding processes
allow omitting of polymer materials (usual in ink-yet
heads) in the new device. The knowledge of materials’
properties is crucial for development of a new MEMS
device for an application facing aggressive media. Both,
the material research and devices for harsh environment
have been addressed by forward looking research at the
MAT. For instance a high temperature pressure sensor
using resistant materials like SiC have been developed
for the use in macro combustion engines.
The simulation of MEMS devices with FEA is standard
at MAT. The MAT has great experience with MEMS actuators.
Besides micro motors, micro mirrors, a micro relay even
two ink-jet devices have been developed. The ink-jet
devices have been made together with commercial partners
and show the high degree of knowledge at the MAT about
this kind of micro actuators. One of these devices,
which has been the first ever with on-chip CMOS circuit,
is a bubble jet called ‘Backshooter’, thermally
actuated. The possibility of FEA modelling in advance,
the experience with the bubble jet, the materials for
harsh environments or aggressive media and the bonding
technology will be combined in the VIMPA project. The
MAT has also developed electronics for control and signal
processing, mainly in the field of sensors. All devices,
which have been made at the MAT, have been characterized
and tested using computer controlled test equipment,
available. Appropriate interface technology and electronics
can be developed. |
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