Non-mechanical variable apertures based on poly(3,4-ethylenedioxythiophene) (PEDOT)

A concept of non-mechanical optical apertures with variable spatial transmission is presented. It is based on electrochromic materials which are capable of changing their transmission when an electrochemical potential is applied. In our case an intrinsically conductive polymer was electrodeposited on an underlying conductive yet translucent layer structured to form the aperture geometry. Operating this aperture as working electrode in an electrochemical three-electrode-cell allowed homogeneous as well as spatial control of its transmission. The feasibility of a purely electrically controlled aperture was demonstrated presenting a grey filter and a linear filter of continuous and digital-like behaviour. (C) 2011 Elsevier B.V. All rights reserved.