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Lab-on-a-Chip (LoC) systems offer the opportunity of fast and customized biological analyses executed at the 'point-of-need' without expensive lab equipment. Some biological processes need a temperature treatment, therefore a technology platform with an integrated heating functionality has been previously described. It is important to ensure stable and homogeneous thermal conditions for biological reactions in the respective biosensor area. Targeting a good homogeneity of the temperature distribution in the sensor area, the use of multiple heaters is beneficial to control the position and shape of hot spots during heating

This work deals with in-line measurement techniques for quantification of important microsystems parameters and related scattering caused by the process conditions. Material properties, mechanical stress but also geometrical dimensions and their tolerances are characterized by indirect method, based on specially designed test-structures. This method involves a data fusion process that combines numerically calculated and experimentally determined information to estimate sought parameters. Laser Doppler Vibrometrie is used to determine the frequency response function (FRF) of the test-structure and find out their Eigenfrequencies. For the numerical simulation of the test-structures a parametrical finite element (FE) model is used and a series of pre-stressed modal analyses have been performed. Hence the dependence of the Eigenfrequencies on parameters of interest is obtained. The comparison to the measured frequencies yields the values of the desired parameters. The test-structures are designed, produced and used for microsystems manufacturing monitoring in Bonding and Deep Reactive Ion Etching (BDRIE) processes. An optimization of the teststructures' form for a nontrivial goal function is shown. Measurement results of the presented technique are comparable with results of common characterization methods. The presented technique is both in-situ and non-destructive

Lab-on-a-chip (LoC) systems offer the opportunity of fast and customized biological analyses executed at the ‘point-of-need’ without expensive lab equipment. Some biological processes need a temperature treatment. Therefore, it is important to ensure a defined and stable temperature distribution in the biosensor area. An integrated heating functionality is realized with discrete resistive heating elements including temperature measurement. The focus of this contribution is a design methodology and evaluation technique of the temperature distribution in the biosensor area with regard to the thermal-electrical behaviour of the heat sources. Furthermore, a sophisticated control of the biosensor temperature is proposed. A finite element (FE) model with one and more integrated heat sources in a polymer-based LoC system is used to investigate the impact of the number and arrangement of heating elements on the temperature distribution around the heating elements and in the biosensor area. Based on this model, various LOC systems are designed and fabricated. Electrical characterization of the heat sources and independent temperature measurements with infrared technique are performed to verify the model parameters and prove the simulation approach. The FE model and the proposed methodology is the foundation for optimization and evaluation of new designs with regard to temperature requirements of the biosensor. Furthermore, a linear dependency of the heater temperature on the electric current is demonstrated in the targeted temperature range of 20 °C to 70 °C enabling the usage of the heating functionality for biological reactions requiring a steady-state temperature up to 70 °C. The correlation between heater and biosensor area temperature is derived for a direct control through the heating current.

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