Under the wings of the Esprit program, researchers from various universities, institutes and laboratories throughout Europe since 1993 are engaged in a long term project called BARMINT. Together, they work on the identification of processes and tools needed for the development of microsystems. The results of their research form a substratum of elements to be used for the production of medical and other devices. Recently, a demonstrator has been finished which includes a micropump, a multisensor measuring chamber and the allied electronic technologies, the whole associated with 3-D assembly processes.
In several countries, the BARMINT project is concretising itself in a variety of angles towards the main concept. The Institut National Polytechnique de Grenoble (INPG) has built a CMP microsystem whereas the Technische Hochschule Darmstadt has developed a translator concept and behaviour model. The Centro Nacional de Microelectronica has specialised itself in CMOS and sensor technology compatibility while both the Laboratoire d'Analyse et d'Architecture des SystËmes (LAAS-CNRS) and the National Microelectronics Research Centre (NMRC) have been concentrating on the production of a micropump and on 3-D assembly technologies. Finally, models and tools for thermal, thermo-mechanical and functional simulation are the major research field for the Universities of Barcelona, Budapest and Lodz.
The Finite Element Modelling (FEM) technique is frequently used in association with microsystems. Both LAAS and the NMRC have applied this method to simulate the packaging-induced stresses on the micropump of the BARMINT demonstrator. The stress must be kept as low as possible in a 3-D package so as not to destroy the device. Therefore, the search for the right materials is capital. The NMRC tried out two different approaches: one based on stacked PCB and spacer units and another one based on Plastic Leadless Chip Carriers (PLCCs). The latter turned out to be the most satisfactory solution. Since PLCC is a standard off-the-shelf component, it lends itself towards bulk manufacturability and is cost saving on top of it.
These research examples may not appear to be very spectacular, yet they constitute a basic part in the production and commercialisation of several medical devices such as implantable micropumps for heart deficiency and bloodflow control or regulated drugs release and microsystems-based prostheses. In this regard, it might be illustrative to put for once on the forefront these undercover researchers.