A method for arranging a plurality of thermally isolated microstructures over at least one cavity, each of the microstructures housing at least part of a thermally-trimmable resistor, the thermally-trimmable resistor having at least a functional resistor, the method comprising: providing pairs of facing microstructures; grouping together sets of pairs of facing microstructures, each of the sets having at least one pair of facing microstructures; and arranging microstructures within a given set to have each microstructure exposed to heat from a same number of facing, side, and diagonal neighbors of microstructures from a same resistor.