Exploratory science learning in a high school curriculum, using structured materials and light polarization

Abstract

Utsunomiya Girls' High School has participated in the national “Super Science High School” science education program for ten years. The program aims to improve advanced science education in high school and to let advanced high school students experience open scientific inquiry, through collaboration with researchers at Utsunomiya University. Our group of students is currently involved in studying the structural color of insects - a topic that brings together chemistry, biology, and optics. Therefore, even students who do not study physics are exposed to interesting optical phenomena. It is well known that beetles' shells exhibit circular polarization, but among similar insects, one will show circular polarization while others do not. Our initial investigation involved imaging the shells of several beetles with an imaging Stokes polarimeter and an electron microscope. As a result, we were able to observe the structural differences between the two types of insects. Next, we tried to experimentally reproduce the same structures using a cholesteric liquid crystal having properties similar to the beetle shells. This provides a means of not just observing but also experimentally investigating structural color of insects.