New research project on chilled food logistics and processing

The art of tuna defrosting

A micromachined, membrane based, thermoelectric flow sensor for 2-dimensional measurement with high angular resolution  

Nico Hartgenbusch Mykhailo Borysov Reiner Jedermann, Walter Lang

This paper introduces a novel membrane based, thermoelectric flow sensor for measuring flow velocity and angle in a plane. With a size of 2 mm in square it is much smaller than comparable sensors; nevertheless it reaches an angular resolution of one degree. It is fabricated in a surface micromachining process and consists of a heater and four thermopiles, embedded in a SiN membrane. The sensor was invented to measure air flow distribution in cooled storage rooms for apples in order to enable a real-time control of the fans to reduce their power consumption. Due to the SiN membrane it’s furthermore possible to operate the sensor with various gases and liquids.

Additional presentation about integration of pressure sensors with RFID technology:

Wireless Piezoresistive Pressure Sensors Used for Quality Control in Glass Fiber Composite Laminates

Minerva Gabriela Vargas Gleason, Reiner Jedermann, Adli Dimassi, Walter Lang

The production of new glass fiber composite parts is, to some extent, a trial-and-error process, which leads to high production costs and material waste. Embedding piezoresistive pressure sensors into composites during the manufacturing process allows for the determination of resin front flow and assists in preventing voids, ensuring complete fiber impregnation during infusion. This reduces material waste and the time required to produce a new part, therefore reducing production costs. When embedding pressure sensors in glass fiber laminates, the wires connecting the sensors often break during the infusion setup, rendering the sensors useless. Wireless pressure sensors solve this problem and simplify the setup required for embedding. In this work, two types of pressure sensors (analog and digital) were connected to a radio frequency identification (RFID) tag and successfully measured the resin flow front during infusion.