Abstract: Example sensor apparatus for microfluidic devices and related methods are disclosed. In examples disclosed herein, a method of fabricating a sensor apparatus for a microfluidic device includes etching a portion of an intermediate layer to form a sensor chamber in a substrate assembly, where the substrate assembly has a base layer and the intermediate layer, and where the base layer comprises a first material and the intermediate layer comprises a second material different than the first material. The method includes forming a first electrode and a second electrode in the sensor chamber. The method also includes forming a fluidic transport channel in fluid communication with the sensor chamber, where the fluidic transport channel comprises a third material different than the first material and the second material.

Abstract: The present disclosure is drawn to an insulated sensor including a silicon substrate with active circuitry on a surface thereof, an electrode disposed on the silicon substrate, a passivation layer having a thickness from greater than 500 Angstroms to 3,000 Angstroms disposed on the active circuitry, and an electrode insulating layer having a thickness from 10 Angstroms to 500 Angstroms disposed on the electrode.

Abstract: A microfluidic diagnostic chip may, in an example, include a number of microfluidic channels defined in a substrate each microfluidic channel fluidly coupled to at least one fluidic slot; the at least one fluidic slot to receive a number of fluids, and a number of gold sensors each gold sensor having a thickness of between 1500 and 5000 angstroms (?).

Abstract: Example implementations relate to coagulation sensing. For example, a microfluidic chip for coagulation sensing may include a microfluidic channel, an outlet at an end of the microfluidic channel having an air interface, and an impedance sensor located within the microfluidic channel and within a particular proximity to the air interface, the impedance sensor to determine a stage of a coagulation cascade of a blood sample flowing through the microfluidic channel to the impedance sensor.

Abstract: A device includes a microfluidic channel structure on a substrate and a first resistive structure on the substrate to control the temperature of at least the substrate. The first resistive structure is separate from, and independent of the, microfluidic channel structure. In some instances, the device includes a second resistive structure.

Abstract: The present disclosure is drawn to an insulated sensor including a silicon substrate with active circuitry on a surface thereof, an electrode disposed on the silicon substrate, a passivation layer having a thickness from greater than 500 Angstroms to 3,000 Angstroms disposed on the active circuitry, and an electrode insulating layer having a thickness from 10 Angstroms to 500 Angstroms disposed on the electrode.

Abstract: Example sensor apparatus for microfluidic devices and related methods are disclosed. In examples disclosed herein, a method of fabricating a sensor apparatus for a microfluidic device includes etching a portion of an intermediate layer to form a sensor chamber in a substrate assembly, where the substrate assembly has a base layer and the intermediate layer, and where the base layer comprises a first material and the intermediate layer comprises a second material different than the first material. The method includes forming a first electrode and a second electrode in the sensor chamber. The method also includes forming a fluidic transport channel in fluid communication with the sensor chamber, where the fluidic transport channel comprises a third material different than the first material and the second material.

Abstract: A device including a substrate and a channel formed in a layer disposed on the substrate. The layer includes a cavitation layer and a passivation layer to mitigate the effects of hydrodynamic cavitation on a surface of the channel. The passivation and cavitation material and thickness are optimized thermally to nucleate and eject a bubble at low voltages. A resistive heating element is disposed within the channel that is activated to create a micro-fluidic pump to advance a fluid through the channel. A sensor is disposed within the channel to measure a characteristic of the fluid passing through the channel.

Abstract: A microfluidic diagnostic chip may, in an example, include a number of microfluidic channels defined in a substrate each microfluidic channel fluidly coupled to at least one fluidic slot; the at least one fluidic slot to receive a number of fluids, and a number of gold sensors each gold sensor having a thickness of between 1500 and 5000 angstroms (?).

Abstract: An electrode system and a method of using an electrode system to make an impedance measurement. The electrode system comprises a substrate that supports a first and second electrodes. The first electrode is located inside a cutout of the second electrode. The first and second electrodes are separated by an insulating layer.

Abstract: A device includes a microfluidic channel structure on a substrate and a first resistive structure on the substrate to control the temperature of at least the substrate. The first resistive structure is separate from, and independent of the, microfluidic channel structure. In some instances, the device includes a second resistive structure.

Abstract: Example implementations relate to coagulation sensing. For example, a microfluidic chip for coagulation sensing may include a microfluidic channel, an outlet at an end of the microfluidic channel having an air interface, and an impedance sensor located within the microfluidic channel and within a particular proximity to the air interface, the impedance sensor to determine a stage of a coagulation cascade of a blood sample flowing through the microfluidic channel to the impedance sensor.

Abstract: In an embodiment, a fluid ejection device includes a fluidic channel having first and second ends and a drop generator disposed within the channel. A fluid reservoir is in fluid communication with the first and second ends of the channel, and an alternating-current electro-osmotic (ACEO) pump is disposed within the channel to generate net fluid flow from the reservoir at the first end, through the channel, and back to the reservoir at the second end.

Abstract: In one embodiment, a fluid ejection device includes a substrate with a fluid slot and a membrane adhered to the substrate that spans the fluid slot. A resistor is disposed on top of the membrane over the fluid slot, and a fluid feed hole next to the resistor extends through the membrane to the slot. A shelf extends from the edge of the resistor to the edge of the feed hole, and a passivation layer covers the resistor and part the shelf. An etch-resistant layer is formed partly on the shelf and in between the fluid feed hole and the resistor.

Abstract: In an embodiment, a fluid ejection device includes a fluidic channel having first and second ends and a drop generator disposed within the channel. A fluid reservoir is in fluid communication with the first and second ends of the channel, and an alternating-current electro-osmotic (ACEO) pump is disposed within the channel to generate net fluid flow from the reservoir at the first end, through the channel, and back to the reservoir at the second end.

Abstract: A method for fabricating a fluid nozzle array includes forming a circuitry layer onto a substrate, the substrate comprising a stopping layer disposed between a membrane layer and a handle layer, forming a fluid feedhole extending from a surface of the membrane layer to the stopping layer, and forming a fluid supply trench extending from a surface of the handle layer to the stopping layer. A fluid nozzle array includes a substrate including a membrane layer, a stopping layer adjacent to the membrane layer, a handle layer adjacent to the stopping layer, and a set of fluid chambers disposed on a surface of the membrane layer above and along a width of a fluid supply trench extending from a surface of the handle layer to the stopping layer.

Abstract: A fluid ejection device includes a thin film heater resistor portion having a heater resistor, and a two-layer structure disposed over the heater resistor. The two-layer structure includes a top layer and a bottom layer, with the top layer having a hardness that is at least 1.5 times greater than the hardness of the bottom layer.

Abstract: In one embodiment, a fluid ejection device includes a substrate with a fluid slot and a membrane adhered to the substrate that spans the fluid slot. A resistor is disposed on top of the membrane over the fluid slot, and a fluid feed hole next to the resistor extends through the membrane to the slot. A shelf extends from the edge of the resistor to the edge of the feed hole, and a passivation layer covers the resistor and part the shelf. An etch-resistant layer is formed partly on the shelf and in between the fluid feed hole and the resistor.

Abstract: A method for fabricating a fluid nozzle array includes forming a circuitry layer onto a substrate, the substrate comprising a stopping layer disposed between a membrane layer and a handle layer, forming a fluid feedhole extending from a surface of the membrane layer to the stopping layer, and forming a fluid supply trench extending from a surface of the handle layer to the stopping layer. A fluid nozzle array includes a substrate including a membrane layer, a stopping layer adjacent to the membrane layer, a handle layer adjacent to the stopping layer, and a set of fluid chambers disposed on a surface of the membrane layer above and along a width of a fluid supply trench extending from a surface of the handle layer to the stopping layer.

Abstract: A fluid ejection device includes a thin film heater resistor portion having a heater resistor, and a two-layer structure disposed over the heater resistor. The two-layer structure includes a top layer and a bottom layer, with the top layer having a hardness that is at least 1.5 times greater than the hardness of the bottom layer.