Function follows form: Analysis and applications of biological and bio-inspired array sensors

For a lot of human applications, array sensors are very useful, even indispensable. Gaining insight in how exactly array function is related to array form might introduce possibilities for improving man-made array sensors. Therefore, this dissertation aims to draw inspiration from natural array sensors, whose function has its roots in their intricate shape.;In order to link function to form for some biological arrays (fish lateral line system, cricket cereal system, bat echolocation system), detailed morphological descriptions of these sensors are required. Initially, this dissertation presents efforts that aim to fill some of the gaps for all three of the systems. It is shown, however, that with micro-CT and MRI scanning techniques, accruing enough morphological information about the systems to link them with functional data is only possible for the bat echolocation system.;Consequently, to link functionality to form, this dissertation uses spatial hearing, as realised in the bat echolocation system, as the system of study. In the relevant literature, the connection between functionality and form what echolocation is concerned, is made by means of the head related transfer function (HRTF) and the directional properties of the emitter. Combined, they form the echolocation related transfer function (ERTF). This dissertation uses a boundary element method (BEM) to extend the present available ERTF knowledge. The process is applied to a specimen of Phyllostomus discolor.;Some bats only make use of a single frequency, or a very narrow band of frequencies, while echolocating. These so-called CF/FM bats cannot rely on spectral features encoded in the ERTF to achieve their localization tasks. In this dissertation, the validity of two hypotheses that rely on temporal spatial cues introduced by the emitter to localize targets, is tested.;After considering the relation between the morphology and the ERTF, a computational model is proposed with which FM-echolocation can be performed. The basic technique on which the method is based, is array Wiener filtering.;Lastly, the directional emission pattern of the bat is incorporated in array processing techniques that determine the acoustical orientation of bats, based on advanced sound propagation models, such as employed in matched field processing (MFP).