Much experience was gained in the JSC in recent years regarding the design and fabrication of arrayed microstructures for the maintenance and measurements of individual biological objects. This includes glass microstructures (A) ranging in size from 5µm to 250µm made via wet etching in BK7 glass using photoresist masks and hydrofluoric acid. These microstructures, due to the excellent optical and biological characteristics of the glass, were directly used for accommodating the cells. An alternate approach is to use the primary microstructured surface as a stamp for embossing in various precursors. In this case, the primary microstructure need not be either optically or biologically inert, thus opening the door for various micromachining methods such as metal electroplating, and dry etching on SiO2 wafers. These stamps in turn, were used to emboss the microstructures using various methods, with precursors of various optically and biologically inert materials, such as PDMS, medical grade optical UV adhesives (B,C), Teflon derivatives, and even porous membranes. Significant knowledge and experience were accumulated in applying surface treatments for the binding or repelling of cells, for hydrophilization, for non-adhesiveness, and for PDMS bonding, using chemicals and/or gas plasma treatment. These technologies were investigated and used in our lab, embedded into cell-carrying vessels such as single cavity microscope slides, Petri dishes and 96-well MTP.

A clip_image002[8] B clip_image002 C clip_image002[4]

                                                                                                                                                                SEM images of microstructure arrays made of glass (A); UV adhesives (B, C).