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J. Matovic, Z. Jaksic:
"A comparative analyze of fundamental noise in cantilever sensors based on lateral and longitudinal displacement: case of thermal infrared detectors";
Microsystem Technologies - Micro- and Nanosystems - Information Storage and Processing Systems, 16 (2010), 755 - 763.

The performance of novel cantilever-based
sensors approaches the limit posed by thermo-mechanical
fluctuations, which is the currently accepted fundamental
detection barrier for micro- and nanomechanical sensors.
At the same time, the sensitivity of a high-level measurement
techniques used for readout of the cantilever displacement
nears the value of 10-14 m/Hz . However, the
thermo-mechanical noise of some cantilever sensors based
on bimaterial structures is considerably higher than
imposed by the fundamental limit. Moreover, the signal-tonoise
ratio of some sensors based on contemporary MEMS
technologies falls behind the characteristics of older
types of mechanical sensors, fabricated using macroscopic
production technologies. To investigate the cause of this
situation, we perform a comparative analysis of the performance
limits for two classes of cantilever sensors: the
bimaterial cantilevers where the output signal is the
transversal (lateral) displacement of the cantilever tip and
the simple cantilever sensors where the signal is the longitudinal
displacement along the cantilever axis. As a
starting point of our analysis we established a correspondence
between the parameters of a bimaterial cantilever
and the simple cantilever. In a general case these two
structures are not directly comparable, since the deformation
of the bimaterial cantilever depends on 14 variables, while
the longitudinal elongation of the simple cantilever
depends on seven parameters only. However, under certain
conditions analyzed in this paper a partial correspondence
between the parameters of these two structures can be
established. Our analysis shows that in certain applications
a cantilever with longitudinal elongation has potentially
better performance than the corresponding bimaterial
element.

http://dx.doi.org/10.1007/s00542-010-1052-6