An artificial iris for light intensity modulation of humanoid robot vision

An artificial iris which adaptively modulating the light intensity of the vision system on humanoid robot is presented. A polymer-dispersed liquid crystal (PDLC) was driven between transparent and opaque states and was sandwiched between indium tin oxide (ITO) electrodes. The ITO electrodes have been patterned so that the light intensity passing through the artificial iris can be tuned in an axisymmetric manner. A control circuit with a photodiode has been developed to drive the artificial iris at 30 V. The fabrication process was detailed. The testing result indicates that the light modulation of the fabricated PDLC increases with the wavelength in the visible spectrum. At the driving voltage of 30 V, the light transmission increases from increases from 24% to 34% for the wavelength of 700 nm.