Abstract: A temperature control device (2) comprises a number of active thermal sites (6) disposed at respective locations on a substrate (10), each comprising a heating element (13) for applying a variable amount of heat to a corresponding site of a medium and a thermal insulation layer (16) disposed between the heating element and the substrate. At least one passive thermal region (8) is disposed between the active thermal sites (6) on the substrate (10), each passive thermal region (8) comprising a thermal conduction layer (18) for conducting heat from a corresponding portion of the medium to the substrate (10). The thermal conduction layer (18) has a lower thermal resistance in a direction perpendicular to a plane of the substrate (10) than the thermal insulation layer (16). This enables precise control over both heating and cooling of individual sites in a flowing fluid, for example.

Abstract: A technique for measuring the resistance of a resistive element 4 in the presence of a series diode is provided. By supplying three different currents I1, I2, I3 and measuring corresponding voltages V1, V2, V3 across the resistive element and diode, the voltages can be combined to at least partially eliminate an error in the measured resistance of the resistive element caused by a voltage drop across the diode. A technique for current control in an array of resistive elements is also described in which a column of resistive elements is provided with two or more current sources switched so that while one current source is providing current to the column line corresponding to a selected resistive element, another current source has its amount of current adjusted.

Abstract: A temperature control device (2) comprises a number of active thermal sites (6) disposed at respective locations on a substrate (10), each comprising a heating element (13) for applying a variable amount of heat to a corresponding site of a medium and a thermal insulation layer (16) disposed between the heating element and the substrate. At least one passive thermal region (8) is disposed between the active thermal sites (6) on the substrate (10), each passive thermal region (8) comprising a thermal conduction layer (18) for conducting heat from a corresponding portion of the medium to the substrate (10). The thermal conduction layer (18) has a lower thermal resistance in a direction perpendicular to a plane of the substrate (10) than the thermal insulation layer (16). This enables precise control over both heating and cooling of individual sites in a flowing fluid, for example.

Abstract: A technique for measuring the resistance of a resistive element 4 in the presence of a series diode is provided. By supplying three different currents I1, I2, I3 and measuring corresponding voltages V1, V2, V3 across the resistive element and diode, the voltages can be combined to at least partially eliminate an error in the measured resistance of the resistive element caused by a voltage drop across the diode. A technique for current control in an array of resistive elements is also described in which a column of resistive elements is provided with two or more current sources switched so that while one current source is providing current to the column line corresponding to a selected resistive element, another current source has its amount of current adjusted.