Field-induced nanoparticle-based membrane pattern design and its application

Abstract

In this thesis, composite functional materials have been studied. Composite functional materials are always composed of several substances, and combine their various advantages and disadvantages. For field-induced particles, such as calcium copper titanate (CCTO) with a huge dielectric constant and carbonyl iron (CI), nickel (Ni) and ferrosoferric oxide (Fe₃O₄) these magnetic particles, they could be easily excited or controlled by external field. As for membrane materials, usually the macromolecule, which are closed related to our daily life, for example, our commonly used plastic bags and plastic wrap are made by PE and PDMS often used in microfluidic chips. Due to their structure and shape they have advantages of high specific strength, high insulation, high elasticity, corrosion and heat resistance, light weight and easy processing. And this thesis combines them to make different field-induced nanoparticle-based membranes and explore their physical properties such as the microstructure, mechanical properties, electric/magnetic field properties, induced patterns, and vibration modes. According to their different properties apply them to achieve different application scenarios. In my research, I used the extraction method to manufacture the porous CCTO-PDMS membranes to realize the ultra-sensitive wide-range small capacitive pressure sensor, as well as realizing a new type of speaker using magnetic membranes as the diaphragm in a force field nonlinear coupling system, and discovered the membrane-type acoustic metamaterials application using the second derivative of the magnetic field to shift the eigenfrequencies of magnetic membranes. It can be seen that field-induced particle-based membrane is a new type of material worthy of our continued exploration, which could empower many application scenarios.

Date of Award	2022
Original language	English
Awarding Institution	The Hong Kong University of Science and Technology
Supervisor	Weijia WEN (Supervisor)