Animal senses cover a broad range of signal types and signal bandwidths and have inspired various sensors and bioinstrumentation devices for biological and medical applications. Insects, such as desert ants and honeybees, for example, utilize polarized skylight pattern-based information in their navigation activities. They reliably return to their nests and hives from places many kilometers away. The insect navigation system involves the dorsal rim area in their compound eyes and the corresponding polarization sensitive neurons in the brain. The dorsal rim area is equipped with photoreceptors, which have orthogonally arranged small hair-like structures termed microvilli. These are the specialized sensors for the detection of polarized skylight patterns (e-vector orientation). Various research groups have been working on the development of novel navigation systems inspired by polarized skylight-based navigation in animals. Their major contributions are critically reviewed. One focus of current research activities is on imitating the integration path mechanism in desert ants. The potential for simple, high performance miniaturized bioinstrumentation that can assist people in navigation will be explored.
Light-matter interaction has been profoundly studied for sample material classification. However, the optical classification of the sample through the polarized light-matter interaction remains underexplored. It is limited to the measurement of intensity instead of the angle of polarized light (AOP) for its degree of polarization. Measurement of the degree of polarization within a material or a medium becomes easier with a simple, low-cost and direct measurement without the need of any probing or labelling agent. Thus, this investigation was conducted mainly to determine the angle of polarized light (AOP) property of the crosslinked polymer using our proposed polarization measurement technique as an alternative approach of the material classification. The angle of polarized light (AOP) of each polymer was determined in combination property of polarization by absorption, transmission, and scattering. Our proposed scattered angle (ס=90°, 100°, 110°, and 120°) successfully measured the AOP of each polymer that can be classified into two groups. Group 1 represents the AOP value ( [Formula: see text] ) for a test sample of t1 = 3.1 %, 3.2, and 3.3 % with comparison to the normal sample (n = 3.0 %) and Group 2 represents the AOP value ( [Formula: see text] ) for the test sample oft2 = 3.4 %, 3.6 % and 3.7 % with comparison to the normal sample (n = 3.0 %). Our study proved a direct, easy, and simple method of determining the degree of polarization of the polymers without the need of complex formulation and labelling protocol. Therefore, this work may enhance the investigation of the optical properties of the agarose-based tissue-mimicking phantom (AGTMP) for modeling or simulation of the real biological sample in the future. Our polarization measures are worthy of further explored and implemented in current optical imaging techniques or sensing platform for optical classification of the biomaterials.