Abstract: Methods and systems for creating patterns in tissue growth for tissue engineering are disclosed. In one embodiment, a method for arranging biological cells along predetermined patterns using an ultrasound includes: emitting the ultrasound by an ultrasound transducer; transmitting the ultrasound through a holographic lens toward a plurality of cells; and generating a pressure field in the predetermined patterns. The predetermined pattern includes a plurality of mutually parallel transverse planes. The parallel transverse planes are configured to entrap groups of cells of the plurality of cells. The axial pressure gradients within the parallel transverse planes are smaller than a first predetermined threshold. The lateral pressure gradients within the parallel transverse planes are larger than a second predetermined threshold. In response to generating the pressure field, the groups of entrapped cells are aligned within parallel transverse planes.

Abstract: A cryogenic pumping system for pumping a cryogenic fluid generally includes a rotor having a plurality of slots. The rotor includes at least one endring defining a plurality of openings. Each opening is aligned with a different one of the slots. A plurality of rotor bars are each positioned within a different one of the slots. Each rotor bar includes an end portion received within a different one of the openings and welded to the endring. The cryogenic pumping system can be used to pump a cryogenic fluid from a first location to a second location.