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polarizers, some waveguides, and many lasers. [1][2][3] Materials with powerful optical functionalities, including negative-index of refraction and optical chirality, can be realized by appropriate placement of materials with suitable properties in 2D or 3D space. [4][5][6] Light in the visible spectrum can be manipulated, although the tolerance for defects is exceedingly low at visible frequencies, and the number of materials with the appropriate properties is limited. [7,8] Most photonic crystals are fabricated by high-resolution top-down 2D patterning methods such as electron-beam lithography, interference lithography, and focused ion beam milling. [9] However, it is challenging to fabricate large-area bulk materials with these techniques, especially with intricate internal structures. [8] Additionally, many materials with promising optical properties are not compatible with these top-down patterning methods. [4,10] As work on colloidal crystals has shown, controlled self-assembly is an effective route to organizing materials into 3D architectures, which interact strongly with light. [9][10][11][12][13] Colloidal self-assembly, however, only offers a limited set of symmetries (generally those of close packed arrangements), and a spherical basis. [12] For many applications, considerably more complex structures are of interest. Particularly promising approaches for forming materials with complex internal microstructures include eutectic solidification and block copolymer self-assembly, [14][15][16][17] and materials with interesting optical properties have been reported using both approaches. These methods are advantageous due to the wide range of microstructures they form. Here, we focus on the structures formed by eutectic solidification since materials with a broader range of optical properties are available compared to that provided by block copolymers, and because the characteristic lengths of structures accessible through eutectic solidification better match the wavelengths of visible and IR light. Further, forming materials with sufficiently large characteristic dimensions for interaction with visible light by block copolymer assembly is synthetically challenging as it requires high molecular weight polymers. [18] Similarly, self-assembly of other building blocks, e.g., nanoparticles, [19,20] molecules, [21,22] and DNA, [23,24] tend to produce structures with characteristic dimensions too small to provide strong light-matter interactions (via diffractive phenomena), [2,3,25] and are thus not the emphasis of this review.Mesostructured materials can exhibit enhanced light-matter interactions, which can become particularly strong when the characteristic dimensions of the structure are similar to or smaller than the wavelength of light. For controlling visible to near-infrared wavelengths, the small characteristic dimensions of the required structures usually demand fabrication by sophisticated lithographic techniques. However, these fabrication methods are restricted to producing 2D and a limited range of 3D...

Although women make up a significant portion of the college educated population, there remains a sizable gap between the number of men and women pursuing degrees and careers in science, technology, engineering and math (STEM) fields. The gender gap begins at middle school and widens considerably in later high school years. One major factor for this gap is the lack of belonging women can feel towards engineering. As one approach to developing and improving this sense of belonging, we focused on improving students' comprehension of engineering topics during a weeklong materials science and engineering summer camp for high school girls. We took a two-prong approach: a unifying paradigm and a design project. The purpose of this was to allow for transfer of learning throughout the week, allowing the students to build and showcase their own comprehension. The paradigm, the materials science tetrahedron, provided cohesion throughout an otherwise broad and seemingly disconnected field, while the design project allowed for students to implement what they learned during the week in a group setting. This approach concomitantly enhances confidence and their sense of belonging within engineering. In this paper we highlight lessons learned from incorporating this approach into our program, including our perception of its effectiveness and feedback from the girls. The preliminary results show that our summer camp is a unique and well-suited opportunity to study how comprehension can engender a sense of belonging amongst female students with the ultimate goal of closing the gender gap in engineering fields. IntroductionThere is still a sizable gap between the number of men and women pursuing degrees and careers in science, technology, engineering and math (STEM) fields 1 . Over the past decade much research has been done to understand the phenomenon known as the gender gap 2,3 . This issue is complex; one main factor being gender stereotypes. By the time women reach high school; negative stereotypes are fairly well ingrained. They have received messages about gender identity and expectations, intentional or not, from parents, teachers, and even through more feminine extracurricular activities such as Girl Scouts 4 . This can lead to a more critical selfassessment in math and science as well as the belief that young women must have exceptional performance in the STEM fields in order to be successful 5 , which is detrimental and can deter women from pursuing these areas.

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