Micro-manipulation of silicate micro-sized particles for biological applications

There are great challenges in biological research to study mechanical or chemical interactions between biological objects and artificial parts, to analyse the biocompatibility of artificial materials and/or to increase knowledge about biological cells. Some interaction studies between cells and artificial objects require to positioning very small objects whose typical size is comparable with cell’s size (typically 5-20 micrometers). This paper presents design, building and testing of a new micro-manipulation station able to grasp, transport and release ten micrometers objects. Devoted to an existing piezoelectric microgripper, innovative end-effectors in silicon have been designed after several mechanical studies. They have been built with microfabrication processes (DRIE1) in SOI 2 wafers. For the application, the positioning of silicate crystals which contain iron close to E-Coli bacteria, new end-effectors were glued on the piezoelectric microgripper. Mounted on a three axis micropositioning stage under a videomicroscope, this innovative microgripper is able to grasp a silicate crystal of 15 micrometers in the air and release it in the bacteria liquid medium.