6
1
Sensors in Micro- and Nanotechnology
The further development of signal processing in the next
10
years will involve primarily the
bringing together of sensor and signal processing at the site of the measurement, and also the
processing of measured values by intelligent devices. Problems that still need to be solved here
lie in the field of manufacturing processes that will provide these integration steps, and in the
mastering of increased reciprocal effects as a consequence of miniaturization. The availability
of
suitable signal-processing concepts and design tools will be of decisive importance to fur-
ther developments here. In addition to signal processing on an electrical basis, implementa-
tions
of
a non-electrical type will be increasingly needed; for example, optical and acoustic
signal processing and transmission, ultrasonic and surface applications, and biocybernetic
systems. In this connection, high-temperature electronics will become increasingly more im-
portant. After the year
2000,
complete, intelligent microsystems will be available. They will
function as independent, teachable, or adaptable systems, will have geometries extending
down into the nano range, will include non-electrical signal processing components, and will
be based partly on materials from high-temperature electronics.
1.2.4
Testing and Diagnosis of Sensor Microsystems
Suitable self-testing and diagnostic components and the testing of supportive signal-
processing algorithms can be anticipated even simultaneously with the design of sensor
microsystems, and these will go beyond previous procedures used in the development of
microelectronic circuits. For physical and chemical functions to be adequately tested in com-
plex systems additional “test sensors” may have
to
be implemented. Via suitable diagnostic
interfaces these test components are to be coupled with external diagnostic facilities in order
thereby to test the functionality of the systems under real conditions.
Therefore, in the future, we must go over to unified and system-overarching strategies and
signal processing concepts for the testing of microsystems.
1.2.5
Malfunction Susceptibility, Reliability
In the future, concepts going beyond this will be decisive in terms of staying competitive.
One significant deficiency of microsystems is paradoxically their malfunction susceptibility.
The significant advantage of an increased reliability by way of a homogeneous constructive
and connective engineering should not be allowed to obscure the fact that in case of a
breakdown, for example,
of
an interconnection or of a component, a microsystem can at best
only detect its non-functionality. This basic malfunction susceptibility could possibly be
removed by
a
massive parallelization of the processing chain. Materials with inherently in-
telligent properties are under discussion for this purpose (see Section
1.2.7).
In the extreme
case, these materials combine sensor, actuator, and signal processing. Two classes should be
distinguished: materials that when exchanged for unintelligent materials increase operational
reliability in familiar electronic systems, and materials that perform their function in-
dependently, without electronics. The latter have the advantage of being able to work totally
without an electrical power supply.