Patrick Ginet

Microsystems elements based on free-standing thick-films made with a new sacrificial layer process

A new process derived from screen-printing technology and based on thick sacrificial layers has been developed in our laboratory for the fabrication of films partially released from the substrate. The sacrificial layer acts as a stable mechanical support during the firing of the active layer and is totally removed after the final thermal treatment of the sample. Fabrication of a copper electrothermal actuator was undertaken to demonstrate the efficiency of this simple, collective and low cost process. Passive components based on this new process include the fabrication of heating resistors, strain gauges and microchannels. Moreover, the process can also be used to facilitate the implementation of piezoelectric devices.

New sacrificial layer based screen-printing process for free-standing thick-films applied to MEMS

Thick-film sacrificial layers based on inorganic materials have been used for the fabrication of free-standing screen-printed films. A specific polymer ink based on a mixture of epoxy and strontium carbonate has been prepared for screen-printing of the sacrificial layer. After deposition and subsequent heat treatments of the structural and sacrificial layers, the latter is removed in an aqueous solution. The harmlessness and efficiency of the process have been demonstrated with regard to the structural layer(s). This new process, initially developed in our laboratory for the fabrication of a cantilever type beam, has been extended to the elaboration of an electrothermal actuator, constituted of two linked copper beams of different widths. The beams are partially suspended above the substrate to which they are anchored. Other developments include the fabrication of heating resistors and microchannels. Moreover, the process has been shown to facilitate the implementation of microassemblies such as piezoelec...

New Screen-printed Thermal Microactuator

A new process derived from the screen-printing technology and based on thick-film sacrificial layers has been developed for the fabrication of electrothermal microactuators. Studies of physico-chemical and functional properties of the actuator as well as comparison with analytical simulations confirm the validity and efficiency of the process. Compared to silicon, the metallic electrothermal actuator offers the possibility of producing small deflections with large driving forces. Preliminary experiments and simulations show that the buckling effect would be suitable for applications with such thick-film metallic actuators.