Abstract: According to examples, an apparatus may include a substrate having a fluid recirculation channel and a membrane adjacent to the fluid recirculation channel, in which the membrane is portion of the substrate having a smaller thickness than other portions of the substrate. The apparatus may also include a component layer, in which a fluid ejection chamber may be formed in the component layer. The fluid ejection chamber may include a nozzle and fluid may be received into the fluid ejection chamber through an inlet port and recirculated to the fluid recirculation channel through an outlet port. The apparatus may further include active circuit elements formed on the membrane, in which the active circuit elements may control ejection of fluid from the fluid ejection chamber through the nozzle.

Abstract: In some examples, a fluid flow meter for a conduit to carry a fluid, includes a first voltage connection point, a second voltage connection point, and a heater. The fluid flow meter includes a plurality of resistive sensors comprising a first resistive sensor on a first side of the heater and a second resistive sensor on a second side of the heater, wherein the first resistive sensor and the second resistive sensor are connected in series between the first voltage connection point and the second voltage connection point, wherein a sense connection point between the first resistive sensor and the second resistive sensor is to output a sense voltage that provides an indication of a fluid flow in the conduit.

Abstract: In some examples, a fluidic die includes an arrangement of fluidic elements to dispense a fluid, where each fluidic element of the fluidic elements includes a fluidic actuator and a fluid chamber. The fluidic die includes an array of fluid feed holes in a plurality of dimensions to communicate the fluid with the fluidic elements, where each of multiple fluid feed holes along a first dimension of the plurality of dimensions is distinct from multiple fluid feed holes along a second dimension of the plurality of dimensions. The fluidic die includes circuit elements interspersed in regions between the fluidic elements along different axes of the fluidic die, where each circuit element of the circuit elements includes an active device. The fluidic elements and the circuit elements are formed on a common substrate.

Abstract: In some examples, a fluidic die includes an arrangement of fluidic elements to dispense a fluid, each fluidic element of the fluidic elements including a fluidic actuator and a fluid chamber. An array of fluid feed holes is arranged in a plurality of dimensions to communicate the fluid with the fluidic elements, where each of multiple fluid feed holes along a first dimension of the plurality of dimensions is distinct from multiple fluid feed holes along a second dimension of the plurality of dimensions. The fluidic die includes first circuit elements operable at a first power supply voltage, the first circuit elements interspersed in regions between the fluidic elements along different axes of the fluidic die.

Abstract: An example fluid ejection device comprises a plurality of distinct fluid channels. Each fluid channel comprises a distinct fluid inlet to the ejection device. A subset of the plurality of distinct fluid channels comprises fluid recirculating fluid channels, and the remaining fluid channels comprising non-recirculating fluid channels.

Abstract: According to an example, a method for performing maintenance routines in a plurality of actuators comprises firing a set of actuators at different energies, determining turn on energy values for the set of actuators based on measurements measured via chamber sensors associated with the set of actuators at the different energies, determining turn on energy differences for the set of actuators based on the turn on energy values determined for the set of actuators and threshold turn on energy values associated with the set of actuators, and performing maintenance routines corresponding to the determined turn on energy differences.

Abstract: In some examples, a fluidic die includes fluidic actuators, switches, and electrically conductive lines in an electrically conductive layer of the fluidic die. The electrically conductive lines electrically connect the switches to respective actuators. A first dimension of a first electrically conductive line is different from a second dimension of a second electrically conductive line to match a first resistance of the first electrically conductive line having a first length to a second resistance of the second electrically conductive line having a second length different from the first length.

Abstract: In some examples, a fluidic die includes an arrangement of fluidic elements to dispense a fluid, each fluidic element of the fluidic elements including a fluidic actuator and a fluid chamber. An array of fluid feed holes is arranged in a plurality of dimensions to communicate the fluid with the fluidic elements, where each of multiple fluid feed holes along a first dimension of the plurality of dimensions is distinct from multiple fluid feed holes along a second dimension of the plurality of dimensions. The fluidic die includes first circuit elements operable at a first power supply voltage, the first circuit elements interspersed in regions between the fluidic elements along different axes of the fluidic die.

Abstract: In some examples, a fluidic die includes an arrangement of fluidic elements to dispense a fluid, where each fluidic element of the fluidic elements includes a fluidic actuator and a fluid chamber. The fluidic die includes an array of fluid feed holes in a plurality of dimensions to communicate the fluid with the fluidic elements, where each of multiple fluid feed holes along a first dimension of the plurality of dimensions is distinct from multiple fluid feed holes along a second dimension of the plurality of dimensions. The fluidic die includes circuit elements interspersed in regions between the fluidic elements along different axes of the fluidic die, where each circuit element of the circuit elements includes an active device. The fluidic elements and the circuit elements are formed on a common substrate.

Abstract: According to examples, an apparatus may include a substrate having a fluid recirculation channel and a membrane adjacent to the fluid recirculation channel, in which the membrane is portion of the substrate having a smaller thickness than other portions of the substrate. The apparatus may also include a component layer, in which a fluid ejection chamber may be formed in the component layer. The fluid ejection chamber may include a nozzle and fluid may be received into the fluid ejection chamber through an inlet port and recirculated to the fluid recirculation channel through an outlet port. The apparatus may further include active circuit elements formed on the membrane, in which the active circuit elements may control ejection of fluid from the fluid ejection chamber through the nozzle.

Abstract: An example fluid ejection device comprises a plurality of distinct fluid channels. Each fluid channel comprises a distinct fluid inlet to the ejection device. A subset of the plurality of distinct fluid channels comprises fluid recirculating fluid channels, and the remaining fluid channels comprising non-recirculating fluid channels.

Abstract: In various examples, a fluid ejection device may include a substrate with a fluid feed hole and a corrosion-detecting conductive path or sensor disposed behind a wall of the fluid feed hold. The corrosion-detecting conductive path or sensor may close a circuit in response being exposed to a fluid contained within the fluid feed hole.

Abstract: A fluidic die may include a substrate supporting a fluid actuator address line and first and second groups of fluid actuators connected to the fluid actuator address line. The first group of fluid actuators may include first and second types of fluid actuators having different operating characteristics. The second group of fluid actuators may include the first and the second types of fluid actuators. The fluid actuators of the first and second groups have addresses such that a fluid actuator of the first type in the first group and a fluid actuator of the second type in the second group are both enabled in response to a single enabling event on the fluid actuator address line.

Abstract: A fluidic die may include a substrate supporting a fluid actuator address line and first and second groups of fluid actuators connected to the fluid actuator address line. The first group of fluid actuators may include first and second types of fluid actuators having different operating characteristics. The second group of fluid actuators may include the first and the second types of fluid actuators. The fluid actuators of the first and second groups have addresses such that a fluid actuator of the first type in the first group and a fluid actuator of the second type in the second group are both enabled in response to a single enabling event on the fluid actuator address line.

Abstract: A fluidic die may include a substrate supporting a fluid actuator address line and first and second groups of fluid actuators connected to the fluid actuator address line. The first group of fluid actuators may include first and second types of fluid actuators having different operating characteristics. The second group of fluid actuators may include the first and the second types of fluid actuators. The fluid actuators of the first and second groups have addresses such that a fluid actuator of the first type in the first group and a fluid actuator of the second type in the second group are both enabled in response to a single enabling event on the fluid actuator address line.

Abstract: According to examples, an apparatus may include fluid chambers that each includes a fluid actuator and an electrode. The fluid actuators may operate at a first voltage level and a monitoring circuitry may operate at a second voltage level that is lower than the first voltage level. The monitoring circuitry may monitor a condition of each fluid chamber based on a selection signal for selecting an electrode associated with a fluid chamber. The monitoring circuitry including an analog multiplexer that includes, for each of the electrodes for the plurality of fluid chambers, a level shifter to receive the selection signal at the second voltage level and to shift a level of the selection signal. The analog multiplexer may also include an analog pass gate to selectively couple the electrode of a respective fluid chamber to the monitoring circuitry based on the level shifted selection signal.

Abstract: A fluidic die includes a substrate and a thermal sensor arranged on a membrane region of the substrate. The substrate includes a fluid slot formed in a back side of the substrate, while the membrane region is positioned between the fluid slot and a front side of the substrate. The substrate also includes a plurality of fluid feed holes in the membrane region, where each fluid feed hole is in communication with the fluid slot and the front side of the substrate.

Abstract: An example input voltage agnostic fluidic device may include a level shifter to adjust an input voltage of control signals received at an input interconnect to a voltage level that is within operational thresholds of on-chip devices of the input voltage agnostic fluidic device.

Abstract: An example input voltage agnostic fluidic device may include a level shifter to adjust an input voltage of control signals received at an input interconnect to a voltage level that is within operational thresholds of on-chip devices of the input voltage agnostic fluidic device. A clamp circuit may be provided to clamp circuitry downstream of the level shifter below the operational threshold of the on-chip device.

Abstract: In some examples, a fluid dispensing device includes a plurality of fluidic actuators and a decoder to detect that a first fluidic actuator is to be activated, and detect that a sense measurement is to be performed. In response to detecting that the first fluidic actuator is to be activated and the sense measurement is to be performed, the decoder is to suppress activation of the first fluidic actuator at a first time, and activate the first fluidic actuator at a second time corresponding to a sense measurement interval to perform the sense measurement of the first fluidic actuator.