Lorenzo Volta
Project Year
Lorenzo


Metasurfaces are structures composed of arrays of meta-atoms with features smaller than the wavelength of incident light. These properties enable precise manipulation of light, supporting versatile platforms for controlling propagation and interaction, including advanced lens systems and photonic devices. This project focuses on the development of bioinspired metasurfaces designed for electrically tunable photonic responses, with a final application toward studying Förster Resonance Energy Transfer (FRET) emissions. The bioinspired design draws from the squid, which can dynamically tune its coloration for camouflage through structural and pigmentary adaptations, an ability emulated through controllable, dynamic optical elements. Holographic lithography, previously employed to fabricate one-dimensional (1D) linear gratings, is extended to define two-dimensional (2D) metasurface patterns on substrates of platinum (Pt) deposited on silicon (Si) wafers. This technique allows the fabrication of periodic features with grating periods adjustable from approximately 200 to 280 nm using a rotation stage, dimensions that enable interactions with visible wavelengths. Additionally, holographic lithography avoids the need for photomasks during optimization, enabling rapid iteration and flexibility in design without the constraints of mask-based processes. Its ability to pattern large areas with nanoscale precision makes it highly suitable for the production of dense, optically active structures. The fabrication process is systematically optimized by adjusting exposure time, development duration, and the rotation angle of the sample holder during lithography to achieve uniform, high-aspect-ratio pillar formations compatible with external electrical stimulation. Following 2D pattern definition, the arrays are coated with a thin layer of high-refractive-index material, such as titanium dioxide (TiO₂), via atomic layer deposition (ALD). These engineered optical platforms will be used to investigate FRET modulation and serve as a foundation for broader studies in tunable and reconfigurable photonic systems.

Major
Physics
University
Chalmers University of Technology
Faculty Sponsor(s):
Michael Gordon
Departments:
Chemical Engineering
Mentor(s):
Victoria Diaz