Année : 2006

The interest in patterning surfaces with microand nanometer resolutions has been growing fast in recentyears, illustrating the tremendous potential of patterning techniques for both fundamental investigationsand technological applications in photonics, molecular electronics, and biosensors. Among the variouspatterning methods, liquid dispensing techniques relying on the use of microcantilevers are verypromising for several reasons. The first one is that they permit a direct patterning of the surface withdifferent kinds of materials without any need for prefabricated patterns. Secondly, alignment of thecantilevers with respect to specific regions on the surface is straightforward since the cantileversthemselves can be used as displacement sensors. Moreover, parallel approaches can be developed to meetspecific requirements in terms of throughput and fabrication costs. In this thesis, we present a liquidspotter (so-called bioplume) based on the use of silicon microcantilevers. Droplets are formed on thesurface by a direct contact method. The fabricated cantilever array is integrated to a closed-loopautomated system allowing the control of the droplet homogeneity and the spatial positioning of themicroarray. The system relies on the use of force sensors, i.e. piezoresistors, integrated into thecantilevers to adjust the trim and to control the deposition parameters, i.e. contact force and time. Byusing a specific external loading chip, different liquids can be loaded onto the cantilevers, enabling theparallel deposition of several entities in a single deposition run. Besides, an electrode is incorporated inthe channel to allow using electrowetting and electrochemistry. The former is used to actively load thecantilever and to control the drop size during delivery, while the latter is used to drive electrochemicalreactions in the deposited picoliter droplets. This tool has been used to print biological solutions, toelectrodeposit copper, to electropolymerize functionalized pyrrole and to directly create crystallinemicrospots of nanobeads. The control of the printed features (resolution, thickness, and composition), theversatility of the printed materials and the added electro-assisted features demonstrate the tremendouspotential of the bioplume tool for research work and industrial applications.