Disclosed are methods and compositions for alternatingly adsorbing and desorbing sorbate molecules by changing the adsorption affinity of polarizable molecular sorbent molecules attached to surfaces of conductors, attached to dielectric materials between the conductors, or attached to both. The conductors and optionally a dielectric material can be arranged as a capacitor.

An electrochemical system having an electrochemical compressor with an operating voltage that is controlled by a controller is described. The operating voltage between a first and second electrodes separated by an ion conducting material, such as a proton conducting polymer, may be oscillated in a waveform. The controller may reduce the voltage to low pressure side of the electrochemical compressor to initiate electrolysis for a set time interval and then may change the operating voltage to operate the electrochemical cell in a compressor mode. When the electrochemical cell is operating in an electrolysis mode, in situ hydrogen is produced on the low pressure side that may be used as a electrochemically active component of the working fluid when the electrochemical cell is switched to a compressor mode. The controller may have a control program that automatically controls the operating waveform as a function of sensor input.

An electrochemical system having an electrochemical compressor with an operating voltage that is controlled by a controller is described. The operating voltage between a first and second electrodes separated by an ion conducting material, such as a proton conducting polymer, may be oscillated in a waveform. The controller may reduce the voltage to low pressure side of the electrochemical compressor to initiate electrolysis for a set time interval and then may change the operating voltage to operate the electrochemical cell in a compressor mode. When the electrochemical cell is operating in an electrolysis mode, in situ hydrogen is produced on the low pressure side that may be used as a electrochemically active component of the working fluid when the electrochemical cell is switched to a compressor mode. The controller may have a control program that automatically controls the operating waveform as a function of sensor input.

Disclosed are techniques such as roll to roll processing to produce inlet valves for controlling entry of fluid into a compartment of a device. The valve includes a body having a compartment and an inlet into the compartment, with the inlet being bifurcated by a pair of spaced wall portions of the body that form a confining region and which pair of spaced wall portions together with wall portions of the body provide a pair of spaced inlet portions into the compartment and a valve member having a first portion that is position-able within a portion of the compartment, an intermediate portion, and a second portion coupled to the first portion by the intermediate portion, with the second portion position-able within the confining region and with the second portion having an obstruction portion.

A network of microfluidic channels may include at least three loops interconnected at a junction. Each of the loops may include a fluid channel having a length extending from the junction to a second end; and a fluid actuator along the fluid channel and located at a first distance from junction along the length of the fluid channel and at a second distance less than the first distance from the second end. Activation of the fluid actuator of selected ones of the at least three loops may selectively produce net fluid flow in different directions about the loops. In one implementation, a fluid channel having a fluid actuator may have a bridging portion that extends over another fluid channel.

A network of microfluidic channels may include at least three loops interconnected at a junction. Each of the loops may include a fluid channel having a length extending from the junction to a second end; and a fluid actuator along the fluid channel and located at a first distance from junction along the length of the fluid channel and at a second distance less than the first distance from the second end. Activation of the fluid actuator of selected ones of the at least three loops may selectively produce net fluid flow in different directions about the loops. In one implementation, a fluid channel having a fluid actuator may have a bridging portion that extends over another fluid channel.

A fluid ejection device may include a first channel having a first end and a second end, a first drop ejector along the first channel, a second channel having a first end and a second end, a second drop ejector along the second channel, a third channel extending between and connecting the first end of the first channel and the first end of the second channel, a fourth channel extending between and connecting the second end of the first channel and the second end of the second channel and a fifth channel extending between and connecting the third channel and the fourth channel.

A fluid ejection device may include a first channel having a first end and a second end, a first drop ejector along the first channel, a second channel having a first end and a second end, a second drop ejector along the second channel, a third channel extending between and connecting the first end of the first channel and the first end of the second channel, a fourth channel extending between and connecting the second end of the first channel and the second end of the second channel and a fifth channel extending between and connecting the third channel and the fourth channel.

A fluid ejection device including, at least, one recirculation system is disclosed. Such recirculation system contains, at least, one drop generator, recirculation channels that include an inlet channel, an outlet channel and a connection channel and a fluid feedhole that communicates with the drop generator via the inlet channel and the outlet channel of the recirculation channel. The recirculation channels can be asymmetrical with reference to the drop generator.

A fluid ejection device including, at least, one recirculation system is disclosed. Such recirculation system contains, at least, one drop generator, recirculation channels that include an inlet channel, an outlet channel and a connection channel and a fluid feedhole that communicates with the drop generator via the inlet channel and the outlet channel of the recirculation channel. The recirculation channels can be asymmetrical with reference to the drop generator.