Versatile micropipette technology based on deep reactive ion etching and anodic bonding for biological applications

A novel, versatile and robust technology to manufacture transparent micropipettes, suitable for biological applications, is presented here. Up to three deep reactive ion etchings have been included in the manufacturing process, providing highly controlled geometry of reservoirs, connection cavities and inlet ports. Etching processes have been used for the definition of chip and reservoir and for nozzle release. Additionally, special design considerations have been developed to facilitate micro-to-macro fluidic connections. Implementation of anodic bonding to seal a glass substrate to the fluidic structure etched on Si, allowed observation of the flow inside the reservoir. Flow tests have been conducted by filling channels with different fluids. Flow was observed under an optical microscope, both during capillary filling and also during pumping. Dispensing has been demonstrated by functionalizing the surface of an AFM cantilever. Mechanical tests performed by piercing live mouse cells with FIB-sharpened micropipettes suggest the design is sturdy for biological piercing applications