Arndt Steinke

Assessment of suspension medium conductivity by means of micro electrodes

Electrolytic conductivity of cell-based suspensions is an important parameter which can be easily and non-destructively measured as part of the electrical impedance. The low frequency conductivity of a cell suspension with very low cell density equals nearly the medium conductivity. However, a high cell density decreases the low frequency conductivity due to the insulating behaviour of the cell membranes. Here we use miniaturized electrode structures, smaller than the size of typical cells for impedometric conductivity measurement which allows an impedance measurement independent of the electrical properties of suspended cells or particles.

Unit for Investigation of the Working Environment for Electronics in Harsh Environments, ESU

When electronic equipment is used in harsh environments with long expected lifetime, there is a need to understand that environment more in detail. This situation is today a reality for many application areas including the automotive sector, heavy industry, the defense sector, and more. To fully understand the working environment, a unit has been developed to monitor physical data such as temperature, vibration, humidity, condensation, etc., to be used in the product development phase for new products. This paper presents the underlying principles for the ESU (Environmental Supervision Unit) and details on the design.

Shortening of the process chain by tactile inline measurement

This article describes the application of a microelectromechanical system (MEMS) with a beam-shaped cantilever and an integrated piezo-resistive measuring bridge. This device is used for a quick inline control of building panels, which consist of different materials (e.g. metals, polymers and elastomers). The micro sensing device distinguishes itself by a comparatively very low probing force (<100 μN), a high natural frequency (<2.7 kHz) and a very small mass (≈ 0.1 mg). Measuring speeds up to approx. 10 mm/s can be realized. In addition, this sensor comes with a typical resolution in vertical displacement of 2 nm (due to noise floor Δf = 1,6 kHz).

New generation of dew point sensors based on LTCC substrate with decoupled contact system

LTCC is used as a substrate for dew point sensor, e.g. multisensing system consisting of detection system for condensation, temperature sensors, stray field sensor for measurement of condensed water mass. All these components as well as through LTCC vias have been integrated in the LTCC substrate. The mentioned through vias enable the separation of corrosive environment from the electric contact system, the cooling element e.g. peltier element and open new application fields for in line measurement of technical and non-technical processes.

Tool of Impedimetric Based Micro-Sensors for Research and Development of Electronic Components

Besides the use of sensors for applications in the automobile, there is an increasing demand for smart sensors that can be applied in the phase of research and development of electronic components for automobiles. For these requirements impedance-based micro-sensors were developed based on a technological platform. One example, the micro condensation sensor, is presented here. Thermally connected to the surface (PCB, components, connector), the microchips reproduce the temperature for the condensation process virtually without error. The detection system recognizes the condensation already in the range of droplet sizes smaller than 5μm and allows measurement up to sizes of 100 micron. The various applications of the tool require hybrid integration and thus guarantee a higher flexibility. There are calibrated, analog or digital output signals for temperature and condensed water mass available to the developer for appropriate applications.