Abstract: An autonomous coverage robot includes a cleaning assembly having forward roller and rearward rollers counter-rotating with respect to each other. The rollers are arranged to substantially maintain a cross sectional area between the two rollers yet permitting collapsing therebetween as large debris is passed. Each roller includes a resilient elastomer outer tube and a partially air-occupied inner resilient core configured to bias the outer tube to rebound. The core includes a hub and resilient spokes extending between the inner surface of the outer tube and the hub. The spokes suspend the outer tube to float about the hub and transfer torque from the hub to the outer tube while allowing the outer tube to momentarily deform or move offset from the hub during impact with debris larger than the cross sectional area between the two rollers.

Abstract: An autonomous coverage robot includes a cleaning assembly having forward roller and rearward rollers counter-rotating with respect to each other. The rollers are arranged to substantially maintain a cross sectional area between the two rollers yet permitting collapsing therebetween as large debris is passed. Each roller includes a resilient elastomer outer tube and a partially air-occupied inner resilient core configured to bias the outer tube to rebound. The core includes a hub and resilient spokes extending between the inner surface of the outer tube and the hub. The spokes suspend the outer tube to float about the hub and transfer torque from the hub to the outer tube while allowing the outer tube to momentarily deform or move offset from the hub during impact with debris larger than the cross sectional area between the two rollers.

Abstract: An autonomous coverage robot includes a cleaning assembly having forward roller and rearward rollers counter-rotating with respect to each other. The rollers are arranged to substantially maintain a cross sectional area between the two rollers yet permitting collapsing therebetween as large debris is passed. Each roller includes a resilient elastomer outer tube and a partially air-occupied inner resilient core configured to bias the outer tube to rebound. The core includes a hub and resilient spokes extending between the inner surface of the outer tube and the hub. The spokes suspend the outer tube to float about the hub and transfer torque from the hub to the outer tube while allowing the outer tube to momentarily deform or move offset from the hub during impact with debris larger than the cross sectional area between the two rollers.

Abstract: Systems and methods for mitigating heat rejection limitations of a thermoelectric module are disclosed. In some embodiments, a method of operating a thermoelectric module includes providing a first amount of power to the thermoelectric module and determining that a temperature of a hot side of the thermoelectric module is above a first threshold. The method also includes, in response to determining that the temperature of the hot side is above the first threshold, providing a second amount of power to the thermoelectric module that is less than the first amount of power. The method also includes determining that the temperature of the hot side of the thermoelectric module is below a second threshold and providing a third amount of power to the thermoelectric module. In some embodiments, this mitigates heat rejection limitations of the thermoelectric module, especially when the hot side of the thermoelectric module is passively cooled.

Abstract: An autonomous coverage robot includes a cleaning assembly having forward roller and rearward rollers counter-rotating with respect to each other. The rollers are arranged to substantially maintain a cross sectional area between the two rollers yet permitting collapsing therebetween as large debris is passed. Each roller includes a resilient elastomer outer tube and a partially air-occupied inner resilient core configured to bias the outer tube to rebound. The core includes a hub and resilient spokes extending between the inner surface of the outer tube and the hub. The spokes suspend the outer tube to float about the hub and transfer torque from the hub to the outer tube while allowing the outer tube to momentarily deform or move offset from the hub during impact with debris larger than the cross sectional area between the two rollers.

Abstract: A method of controlling a heat exchanger including thermoelectric coolers to maintain set point temperature of a chamber. The method includes receiving temperature data indicative of a temperature of the chamber and selectively controlling two or more subsets of thermoelectric coolers based on the temperature of the chamber. Selectively controlling the two or more subsets includes operating each thermoelectric cooler in a first subset at or near the point where the coefficient of performance is maximized (QCOPmax) by providing a current or voltage with amplitude corresponding to QCOPmax (ICOPmax, VCOPmax) when the temperature of the chamber is within a predefined steady state range including the set point temperature.

Abstract: Gallium nitride material devices and methods associated with the same. In some embodiments, the devices may be transistors which include a conductive structure connected to a source electrode. The conductive structure may form a source field plate which can be formed over a dielectric material and can extend in the direction of the gate electrode of the transistor. The source field plate may reduce the electrical field (e.g., peak electrical field and/or integrated electrical field) in the region of the device between the gate electrode and the drain electrode which can lead to a number of advantages including reduced gate-drain feedback capacitance, reduced surface electron concentration, increased breakdown voltage, and improved device reliability. These advantages enable the gallium nitride material transistors to operate at high drain efficiencies and/or high output powers. The devices can be used in RF power applications, amongst others.

Abstract: An autonomous coverage robot includes a cleaning assembly having forward roller and rearward rollers counter-rotating with respect to each other. The rollers are arranged to substantially maintain a cross sectional area between the two rollers yet permitting collapsing therebetween as large debris is passed. Each roller includes a resilient elastomer outer tube and a partially air-occupied inner resilient core configured to bias the outer tube to rebound. The core includes a hub and resilient spokes extending between the inner surface of the outer tube and the hub. The spokes suspend the outer tube to float about the hub and transfer torque from the hub to the outer tube while allowing the outer tube to momentarily deform or move offset from the hub during impact with debris larger than the cross sectional area between the two rollers.

Abstract: Embodiments of a hybrid fan and active heat pumping system are disclosed. In some embodiments, the hybrid fan and active heat pumping system comprises a fan assembly and an active heat pumping system comprises a heat pump. The active heat pumping system is integrated with the fan assembly and is operable to actively cool or heat air as the air passes through the fan assembly. In some embodiments, the heat pump comprised in the active heat pumping system is a solid-state heat pump, a vapor compression heat pump, or a Stirling Cycle heat pump.

Abstract: An autonomous coverage robot includes a cleaning assembly having forward roller and rearward rollers counter-rotating with respect to each other. The rollers are arranged to substantially maintain a cross sectional area between the two rollers yet permitting collapsing therebetween as large debris is passed. Each roller includes a resilient elastomer outer tube and a partially air-occupied inner resilient core configured to bias the outer tube to rebound. The core includes a hub and resilient spokes extending between the inner surface of the outer tube and the hub. The spokes suspend the outer tube to float about the hub and transfer torque from the hub to the outer tube while allowing the outer tube to momentarily deform or move offset from the hub during impact with debris larger than the cross sectional area between the two rollers.

Abstract: Gallium nitride material devices and methods associated with the same. In some embodiments, the devices may be transistors which include a conductive structure connected to a source electrode. The conductive structure may form a source field plate which can be formed over a dielectric material and can extend in the direction of the gate electrode of the transistor. The source field plate may reduce the electrical field (e.g., peak electrical field and/or integrated electrical field) in the region of the device between the gate electrode and the drain electrode which can lead to a number of advantages including reduced gate-drain feedback capacitance, reduced surface electron to concentration, increased breakdown voltage, and improved device reliability. These advantages enable the gallium nitride material transistors to operate at high drain efficiencies and/or high output powers. The devices can be used in RF power applications, amongst others.

Abstract: Gallium nitride material devices and methods associated with the same. In some embodiments, the devices may be transistors which include a conductive structure connected to a source electrode. The conductive structure may form a source field plate which can be formed over a dielectric material and can extend in the direction of the gate electrode of the transistor. The source field plate may reduce the electrical field (e.g., peak electrical field and/or integrated electrical field) in the region of the device between the gate electrode and the drain electrode which can lead to a number of advantages including reduced gate-drain feedback capacitance, reduced surface electron concentration, increased breakdown voltage, and improved device reliability. These advantages enable the gallium nitride material transistors to operate at high drain efficiencies and/or high output powers. The devices can be used in RF power applications, amongst others.

Abstract: Systems and methods are disclosed herein relating to an Alternating Current-Direct Current (AC-DC) power conversion system for supplying power to one or more Thermoelectric Coolers (TECs). In some embodiments, a system comprises one or more TECs and an AC-DC power conversion system configured to supply power to the one or more TECs for a high efficiency mode of operation and a high heat pumping mode of operation. The AC-DC power conversion system comprises a first AC-DC power converter configured to convert an AC input to a DC output at a first output power level for the high efficiency mode of operation of the one or more TECs. The AC-DC power conversion system further comprises a second AC-DC power converter configured to convert the AC input to a DC output at a second output power level for the high heat pumping mode of operation of the one or more TECs.

Abstract: Embodiments of a hybrid fan and active heat pumping system are disclosed. In some embodiments, the hybrid fan and active heat pumping system comprises a fan assembly and an active heat pumping system comprises a heat pump. The active heat pumping system is integrated with the fan assembly and is operable to actively cool or heat air as the air passes through the fan assembly. In some embodiments, the heat pump comprised in the active heat pumping system is a solid-state heat pump, a vapor compression heat pump, or a Stirling Cycle heat pump.

Abstract: A thermoelectric refrigeration system including at least one cooling chamber and a thermoelectric heat exchange system. The thermoelectric heat exchange system includes cascaded heat sinks. The cascaded heat sinks include cascaded cold side heat sinks and a hot side heat sink. The cascaded cold side heat sinks include a first cold side heat sink and a second cold side heat sink. The thermoelectric heat exchange system also includes a first plurality of thermoelectric coolers disposed between the first cold side heat sink and the second cold side heat sink and a second plurality of thermoelectric coolers disposed between the second cold side heat sink and the hot side heat sink. Each thermoelectric cooler is a module including multiple thermoelectric devices.

Abstract: An autonomous coverage robot includes a cleaning assembly having forward roller and rearward rollers counter-rotating with respect to each other. The rollers are arranged to substantially maintain a cross sectional area between the two rollers yet permitting collapsing therebetween as large debris is passed. Each roller includes a resilient elastomer outer tube and a partially air-occupied inner resilient core configured to bias the outer tube to rebound. The core includes a hub and resilient spokes extending between the inner surface of the outer tube and the hub. The spokes suspend the outer tube to float about the hub and transfer torque from the hub to the outer tube while allowing the outer tube to momentarily deform or move offset from the hub during impact with debris larger than the cross sectional area between the two rollers.

Abstract: Semiconductor structures comprising a III-nitride (e.g., gallium nitride) material region and methods associated with such structures are provided. In some embodiments, the structures include an electrically conductive material (e.g., gold) separated from certain other region(s) of the structure (e.g., a silicon substrate) by a barrier material in order to limit, or prevent, undesirable reactions between the electrically conductive material and the other component(s) which can impair device performance. In certain embodiments, the electrically conductive material may be formed in a via. For example, the via can extend from a topside of the device to a backside so that the electrically conductive material connects a topside contact to a backside contact. The structures described herein may form the basis of a number of semiconductor devices including transistors (e.g., FET), Schottky diodes, light-emitting diodes and laser diodes, amongst others.

Abstract: A thermoelectric refrigeration system includes a heat exchanger that includes a cold side heat sink and a hot side heat sink. The thermoelectric refrigeration system also includes a heat exchange loop coupled to one of the cold side heat sink and the hot side heat sink, the heat exchange loop operating according to thermosiphon principles to provide passive two-phase transport of a working fluid through the heat exchange loop. The thermoelectric refrigeration system also includes thermal insulation that thermally insulates the heat exchanger from a cooling chamber of the thermoelectric refrigeration system or an environment that is external to the thermoelectric refrigeration system.

Abstract: An autonomous coverage robot includes a cleaning assembly having forward roller and rearward rollers counter-rotating with respect to each other. The rollers are arranged to substantially maintain a cross sectional area between the two rollers yet permitting collapsing therebetween as large debris is passed. Each roller includes a resilient elastomer outer tube and a partially air-occupied inner resilient core configured to bias the outer tube to rebound. The core includes a hub and resilient spokes extending between the inner surface of the outer tube and the hub. The spokes suspend the outer tube to float about the hub and transfer torque from the hub to the outer tube while allowing the outer tube to momentarily deform or move offset from the hub during impact with debris larger than the cross sectional area between the two rollers.

Abstract: Systems and methods for mitigating heat rejection limitations of a thermoelectric module are disclosed. In some embodiments, a method of operating a thermoelectric module includes providing a first amount of power to the thermoelectric module and determining that a temperature of a hot side of the thermoelectric module is above a first threshold. The method also includes, in response to determining that the temperature of the hot side is above the first threshold, providing a second amount of power to the thermoelectric module that is less than the first amount of power. The method also includes determining that the temperature of the hot side of the thermoelectric module is below a second threshold and providing a third amount of power to the thermoelectric module. In some embodiments, this mitigates heat rejection limitations of the thermoelectric module, especially when the hot side of the thermoelectric module is passively cooled.