10. Sensors and actuators
The integration of sensors and actuators into larger systems can lead to new functionalities and more efficient production in many high-tech systems. The forming of networks is a key element in this. The integration of these sensors allows for innovations in the fields of security and logistics. Similar solutions can also be used to monitor patients, to advance preventive healthcare, and to reduce costs in the medical field. In industry, the implementation of additional sensors can improve performance by predicting essential maintenance and accurate condition monitoring. In the chemical industry this will allow production on a micro scale with macro output. Finally, in printing, it will enable high throughput and high quality.
The following programmes fall under this theme:
10A - Systems and packaging - Prof. dr. U. Staufer (TUD)
10B - Micro nozzles - Dr. ir. H. Wijshoff (Océ)
10C - Microdevices for chemical processing - Dr. ir. M. Blom (Micronit)
10A Systems and packaging
Sensors are essential tools for monitoring the environment and controlling processes in public areas, industrial manufacturing, and health care. It is therefore of socio-economic interest to have available the most performing, robust, and error tolerant sensors. We address this requirement in a first line of attack by implementing thousands of identical sensors, so called 'sensor swarms', which inherently can be error tolerant and due to large number effects achieve unsurpassed system stability. The second strategy focuses on the interface between the sensor and its environment, our everyday world. This contact is provided through the so-called 'package' of the sensor. A thorough understanding of these interfaces will also allow making individual sensors more robust and reliable . The fabrication process of such packaged sensors is called 'heterogenous integrations', because different elements and materials are assembled in one package.
A better understanding of the systems architecture and the heterogeneous integration, assembly and packaging technology enables faster developments with less iterations. Hence less energy will be consumed and less waste produced, in other words, the work contributes to a more sustainable economy. With the overarching goal of industrialization, the program aims at delivering:
- Experimental evidence of the robustness of sensor colonies
- Models for describing multi-scale multi-physics interfaces
- An assembly and packaging technique, for soft systems
- A robust, integrated micro Coriolis flow sensor, controlling a micro-valve
- An imbedded gas-sensing system for harsh environments
- Packaged self calibrating nano-cantilever sensor system
10B Micro nozzles
The behavior of fluids on micro scales is very different from that on large scales, offering both new technological opportunities and new scientific challenges. The formation and precise control of large numbers of miniature fluid volumes enables the production of highly‐uniform microspheres for drug delivery, precisely controlled sprayed and atomized pharmaceuticals and aerosols, deposition of minute amounts of biofluids for medical analyses, high‐throughput high‐resolution inkjet printing, etc. On the other hand, severe complications can arise from uncontrolled behavior of thin‐liquid films: contact‐line instabilities and nanobubbles compromise the reliability of immersion‐lithography processes and cause excessive wetting of inkjet‐nozzle plates, leading to malfunction. The inherent multiphysics and multiscale character of microfluids necessitate an aggregation of disparate knowledge and close public (knowledge) and private (application) cooperation. This program focuses on two essential phenomena:
- Formation of microdroplets: This process is relevant for spray and jetting applications, the production of microspheres, and micro‐etching techniques.
- Control of thin liquid films: This process is relevant for all jetting and immersionlithography applications.
The program connects expert scientific knowledge of microfluidic phenomena and modeling and simulation techniques to device and process development. The program focuses on a selection of applications with direct relevance for the Dutch high‐tech industry.
10C Microdevices for chemical processing
The aim of the program “microdevices for chemical processing” is the development of scalable microstructured reactors and functionalization of microreactors, and the use of these reactors for selected applications, thereby proving the technical and commercial relevance of the use of microdevices in chemical processing. This is essential for the uptake of this technology by industry. The program consists of 2 closely related, clustered projects focusing on:
- channel functionalization (e.g. wetting control, catalyst implementation)
- scalable microstructured reactors
For the microstructured reactors the complete range of channel sizes from 10 μm (researchscale) to several millimetres (required for production) will be covered. The challenge is therefore to obtain a thorough understanding of scaling issues, both focusing on the direct influence on the reaction itself, and on the influence on the reactor performance. This latter effect will especially come into play when creating stacked networks of parallel channels, influencing thermal management and fluid distribution. Furthermore the influence of scaling on sedimentation in microdevices will be studied.
A second scientific focus will be microreactor functionalization, in combination with optical techniques. Work will be centred around 1) new, improved functionalization procedures 2) modeling and simulation of catalytic coatings in microreactors and 3) use of planar waveguides for both coating/catalyst characterization and monitoring the catalytic reactions. All 3 foci involve new research and development and do not overlap with current research.