Abstract: A microfluidic device includes a chamber having sidewalls, a floor, a ceiling, and an inlet. The microfluidic device includes pillars extending from the floor to the ceiling of the chamber. Each pillar has an orientation relative to the inlet defined by a leading surface and a trailing corner opposite the leading corner. The trailing corner has an angle less than a threshold angle that is based on a fluidic contact angle. The orientations of the pillars relative to the inlet promote fluid flow from the inlet throughout the chamber without trapping gas at the sidewalls of the chamber.

Abstract: An example microfluidic mixer can include an inlet microfluidic channel portion and a fluid splitting channel portion including an overpass microfluidic channel to receive fluid from a first side of the inlet microfluidic channel portion and an underpass microfluidic channel to receive fluid from a second side of the inlet microfluidic channel portion, where the underpass microfluidic channel extends under the overpass microfluidic channel such that the channels overlap at their respective downstream ends. A fluid recombining channel portion is downstream of the fluid splitting portion and includes an angled recombining surface having an acute angle with respect to a direction of fluid flow, where the angled recombining surface is between the downstream ends of the overpass and underpass microfluidic channels. An outlet microfluidic channel portion is fluidly connected downstream from the fluid recombining channel portion.

Abstract: In one example in accordance with the present disclosure, a device for conducting a reaction with a fluid sample is described. The device includes: a microfluidic channel; a number of heating elements along the microfluidic channel; and an inertial pump at each of opposite ends of the microfluidic channel to oscillate the fluid sample along the microfluidic channel.

Abstract: In one example in accordance with the present disclosure, a thermal cycling device is described. The thermal cycling device includes a fluid chamber to retain a fluid. A heating element is disposed around multiple sides of a cross-sectional perimeter of the fluid chamber and an insulator is disposed around multiple sides of a cross-sectional perimeter of the heating element. The thermal cycling device also includes a conductive body disposed around multiple sides of a cross-sectional perimeter of the insulator.

Abstract: An example microfluidic structure can include a first microfluidic channel segment in a first elevation plane, a second microfluidic channel segment in a second elevation plane, and a transverse microfluidic channel segment connecting the first microfluidic channel segment to the second microfluidic channel segment. An angled exterior wall segment can be at the transverse microfluidic channel segment. The angled exterior wall segment can be angled in the first or second elevation plane at an acute angle with respect to a direction of fluid flow through the first or second microfluidic channel segment. A fluid cross-sectional area can increase in the fluid flow direction along the angled exterior wall segment.

Abstract: An example microfluidic structure can include a first microfluidic channel segment in a first elevation plane, a second microfluidic channel segment in a second elevation plane, and a transverse microfluidic channel segment connecting the first microfluidic channel segment to the second microfluidic channel segment. An interior pillar can be positioned at the transverse microfluidic channel segment. The interior pillar can have a tapered downstream edge. The tapered downstream edge can be angled in the first or second elevation plane at an acute angle. A fluid cross-sectional area can increase in the fluid flow direction along the tapered downstream edge.

Abstract: Intermittent warming of a biologic sample including a nucleic acid includes receiving at a first end of a channel of a microfluidic device, a biologic sample including a nucleic acid, and warming a subset of a plurality of heating elements disposed adjacent to the channel. The method includes warming the heating elements to a particular temperature of a particular warming and cooling protocol. The method includes moving the biologic sample from the first end of the channel to a second end of the channel opposite the first end at a particular flow rate associated with the warming and cooling protocol, and intermittently warming the biologic sample using the subset of heating elements while the biologic sample moves from the first end of the channel to the second end of the channel.