°C) to perform a direct silicon–silicon bond between the wafer layers. Absence of the bonding layer allows definition of the vertical pump design parameters. Additionally, the bonding layer might be affected by the pumped medium. The compression ratio of the micropump as one of the critical performance indicator is defined as the ratio between the stroke volume, i.e. fluid volume displaced by the pump membrane over the course of the pump cycle, and the dead volume, i.e. the minimum fluid volume remaining in the pump chamber in pumping mode. The compression ratio defines the bubble tolerance and the counter pressure capability of the micropumps. Gas bubbles within chamber hinder micropump operation as due to the damping properties of the gas bubbles the pressure peaks (∆P) in the pump chamber decreases, while due to the surface properties the critical pressure (∆Pcrit) that opens passive valves increases. The compression ratio of Fraunhofer EMFT micropumps reaches the value of 1, which implies self-priming capability and bubble tolerance even at challenging outlet pressure conditions. Large compression ratio is achieved thanks to special patented technique of piezo mounting, when electrical voltage is applied on the electrodes on the top and bottom of the piezoelectric ceramic during the curing process of the adhesive used for the piezo mounting. Considerable reduction of the dead volume resulted from predeflected actuators along with shallow fabricated pump chamber heights increases the compression ratio. Peristaltic micropumps A peristaltic micropump is a micropump composed of at least three microvalves in series. These three valves are opened and closed sequentially in order to pull fluid from the inlet to the outlet in a process known as peristalsis. Non-mechanical micropumps Valveless micropumps Static valves are defined as valves which have fixed geometry without any moving parts. These valves provide flow rectification through addition of energy (active) or inducing desired flow behavior by fluid inertia (passive). Two most common types of static geometry passive valves are Diffuser-Nozzle Elements and Tesla valves. Micropumps having nozzle-diffuser elements as flow rectification device are commonly known as Valveless Micropumps. Capillary pumps In microfluidics, capillary pumping plays an important role because the pumping action does not require external actuation power. Glass capillaries and porous media, including nitrocellulose paper and synthetic paper, can be integrated into microfluidic chips. Capillary pumping is widely used in lateral flow testing. Recently, novel capillary pumps, with a constant pumping flow rate independent of the liquid