Nicolas Blondiaux

Use of Force Spectroscopy to Investigate the Adhesion of Living Adherent Cells

The use of force spectroscopy to study the adhesion of living fibroblasts to their culture substrate was investigated. Both primary fibroblasts (PEMF) and a continuous cell line (3T3) were studied on quartz surfaces. Using a fibronectin-coated AFM cantilever, it was possible to detach a large proportion of the 3T3 cells from the quartz surfaces. Their adhesion to the quartz surface and the effects of topography on this adhesion could be quantified. Three parameters characteristic of the adhesion were measured: the maximum force of detachment, the work of adhesion, and the distance of detachment. Few PEMF cells were detached under the same experimental conditions. The potential and limitations of this method in measuring cell/surface interactions for adherent cells are discussed.

Self-Patterned Nanoparticle Layers for Vertical Interconnects: Application in Tandem Solar Cells

We demonstrate self-patterned insulating nanoparticle layers to define local electrical interconnects in thin-film electronic devices. We show this with thin-film silicon tandem solar cells, where we introduce between the two component cells a solution-processed SiO2 nanoparticle layer with local openings to allow for charge transport. Because of its low refractive index, high transparency, and smooth surface, the SiO2 nanoparticle layer acts as an excellent intermediate reflector allowing for efficient light management.

Nano-Structuring by Molecular Self-Assembly

In contrast to conventional lithography techniques which will soon hit their limits in terms of feature size and fabrication cost, recent years have seen considerable progress in the development of self-assembling nano-structured surfaces. In the work reported here, surface structures on the submicron scale have been created from polymer, copolymer, nanoparticle, and dendrimer building blocks by employing phenomena such as self-assembly, self-organization and non-equilibrium processes. This low-cost approach is expected to result in a new generation of surfaces with novel physical and chemical properties.

Fabrication of Functional Plastic Parts Using Nanostructured Steel Mold Inserts

We report on the fabrication of sub-micro and nanostructured steel mold inserts for the replication of nanostructured immunoassay biochips. Planar and microstructured stainless steel inserts were textured at the sub-micron and nanoscale by combining nanosphere lithography and electrochemical etching. This allowed the fabrication of structures with lateral dimensions of hundreds of nanometers and aspect ratios of up to 1:2. Nanostructured plastic parts were produced by means of hot embossing and injection molding. Surface nanostructuring was used to control wettability and increase the sensitivity of an immunoassay.