A technique for selectively attenuating a radiation exposure in which a configurable
collimator is employed between the radiation source and the radiation target. The
configurable collimator typically comprises an array of independently addressable
elements each of which has at least a high and a low attenuation state, though
intermediate states may also be accommodated. The elements of the array may be
selectively addressed to determine their state and to determine the attenuation
profile of the collimator. One embodiment of the technique employs an array of
microactuated attenuating louvers which may be selectively actuated to determine
their radiation transmittance. A second embodiment of the technique employs a suspension
of attenuating nematic colloids which may be ordered by the application of an electric
or magnetic field. The ordered state of the nematic colloids within an element
determine the radiation transmittance of that element. A third embodiment of the
technique employs microfluidics to fill an array of fluid chambers with an attenuating
fluid. The level of filling within each chamber determines the attenuation produced
by that array element.
