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Pyroelectric detectors are used for gas analysis and flame detection because of their fast response and excellent performance. Most pyroelectric devices are based on monocrystalline lithium tantalate or pyroelectric lead zirconate titanate thin films deposited on a silicon (Si) substrate. In comparison, recently discovered pyroelectric-doped hafnium oxide (HfO 2 ) offers the possibility of manufacturing completely complementary metal-oxide-semiconductor (CMOS)compatible devices on large Si wafers. This is a promising approach to simplifying mass production of the sensor element and realizing new sensor structures with a high performance. Si substrates were structured with trenches and filled with thin-doped HfO 2 layers by atomic layer deposition to multiply the pyroelectric current responsivity. An effective pyroelectric coefficient of up to 1300 μC∕m 2 ∕K was measured. Micromechanical structuring of the 6-in Si wafers was used to improve the thermal conversion of the sensor element. The applied plasmonic absorbers increase the infrared light absorption to >80% for the spectral range of 3 to 5 μm, which was determined using Fourier transform infrared reflection measurements. In the first step, the performance of the sensor element was evaluated with an analog transimpedance amplifier with a feedback resistance of 5 GΩ. A specific detectivity D Ã > 1 • 10 7 cm p Hz∕W was measured for the frequency range of 1 to 10 Hz. In addition, an application-specific integrated circuit was designed for the electrical signal conditioning to build a fully CMOScompatible pyroelectric detector. It offers a simple to manufacture, flexible configuration, and digital communication interface with a signal-to-noise performance close to analog detectors. We present the measurement results of different sensor elements and detector types.

Lightweight structures are gaining importance due to the relevance of saving energy in mobile applications. External stress caused by impacts, deformations or compression injures the composite materials mostly by invisible internal distortions and leads to the degradation of their properties. Thus, an early detection of material damage is significant in applications with a very high level of required reliability. Structural health monitoring (SHM) on demand using functionalised materials can be a solution [1, 2]. The integration of electromagnetic resonators in glass-fibre-reinforced plastics (GFRP) allows the fabrication of materials with passive sensor function used for SHM of composite materials. Conductive patterns with a specific geometry, dimension and alignment show an electromagnetic resonance that can be changed by the arrangement of the resonators or by the surrounded material. Printing technology is an efficient fabrication method regarding resources, time consumption and costs. The additive and selective deposition of conductive ink on flexible substrates shows a great potential to be processed roll-to-roll and subsequently integrated into lightweight structures [3]. The read-out takes place wirelessly by analysing the reflection response of the functionalised structure. The paper considers the modelling, numerical analysis, fabrication and evaluation of a smart structure and its sensor function. Furthermore, in order to create a basis for a successful market introduction and penetration of such innovative smart structures, a concept for an integrated life cycle-related engineering and business modelling [4] is outlined in this paper.

As part of a future optical platform on-chip, we present a waveguide integrated tunable Fabry-Pérot Interferometer (FPI) for the long infrared wavelength range. The FPI consists of two parallel Bragg reflectors that are located at the ends of two waveguides facing each other. The waveguides are made of silicon and are suspended in air. The reflectors are realized as an alternating stack of silicon and air layers with high (H) and low (L) refractive index. The filter transmittance is evaluated by analytic calculations and electromagnetic finite difference time domain simulations. Filters with (HL)² layer stack show a full width half maximum of 270 nm and a peak transmittance of more than 25% at a wavelength of 9.4 µm at the first interference order in the simulation. It is evaluated by measurements.A MEMS actuator is used to tune the filter wavelength by changing the distance between both reflectors. A digital electrostatic actuator concept with a linear drive characteristic, designed for a large travel range up to 4 µm with a driving voltage of less than 30 V, is presented and evaluated together with the filter.The MEMS fabrication process for the structures is based on bonding and deep reactive ion etching (DRIE). The DRIE etch process was optimized, hereafter achieving a reduced roughness of less than 3 nm of the waveguide sidewalls.For transmission measurements the silicon waveguides are coupled to a laser source and a detector using optical fibers together with optical couplers on the chip. The filter performance was characterized in the range from 9μm to 9.4 µm.