BACKGROUND

The present disclosure relates generally to a microfluidic probe head, and to a microfluidic probe.

A microfluidic probe is a non-contact microfluidic system combining concepts of hydrodynamic flow confinement (HFC) and scanning probes for yielding a dynamic microfluidic device which may enable the need for performing analyses within closed conduits. It operates under the well-known Hele-Shaw cell approximation, wherein a quasi-2D Stokes flow is generated between two parallel generally flat surfaces—i.e., plates—separated by an arbitrarily small gap working in a microfluidic dipole and microfluidic quadrupole configuration. Generally, the method may be used for applications such as patterning protein arrays on flat services, mammalian cell stimulations and manipulations, localized perfusion of tissue slices as well as generating floating concentration gradients. Microfluidic probes have been proposed as a tissue lithography tool, and may allow prospective studies of formalin-fixed, paraffin-embedded tissue sections. The technique has also been used in the microfluidic quadrupole configuration, as a tool for advanced cell chemotaxis studies, wherein it may allow studying cellular dynamics during migration in response to moving concentration gradients.

Hence, microfluidic probes (MFP) create hydrodynamic flow confinements with aligned aspiration and injection channels, resulting in tear drop shapes. Vertical MFPs with one aspiration and one injection channel have structures etched on a single surface, leading to aligned apertures for flow confinements. Such a shape can be limiting for certain applications; for example, when large areas need to be processed in a given time or when the objective is to pattern a surface with a user-defined geometry. In order to obtain more adaptable shapes, horizontal MFPs may be fabricated with multiple apertures distributed on a plane for more flexible flow confinement shapes. An increase in shape complexity requires a higher number of apertures and capillary connections. Multiple tear drop-shaped confinements can be combined to create composite geometries.

SUMMARY

According to an embodiment, a microfluidic probe head is provided. The microfluidic probe head comprises a processing surface. The processing surface has a first and second aperture. The microfluidic probe head comprises a fluid injection channel. The fluid injection channel leads to the first aperture. The microfluidic probe head comprises a first fluid aspiration channel. The first fluid aspiration channel leads to the second aperture. The second aperture forms a slot in the processing surface.

According to another embodiment, a microfluidic probe is provided. The microfluidic probe comprises the microfluidic probe head of the embodiment described above.

