Advanced Substrates for Wearable and Printed Electronics
Date of Award
Chemistry and Biochemistry
Elastomer, Electroless deposition, Printed electronics, Strain sensors, Stretchable conductors, Wearable electronics
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This dissertation describes the development of elastomer and paper-based electronics, addressing application-specific challenges in the development of wearable electronics and smart packaging through strategic substrate design.
Chapters 2 and 3 describe the patterned, solution-based metallization of a commercially available, disposable glove to fabricate a wearable strain sensing array. Chapter 2 details the characterization and implementation of this ready-to-wear strain sensing glove. The glove garment acts as a convenient vehicle to carry and easily apply the strain sensing array to the hand joints, while the surface roughness of the glove facilitates the formation of a reticular cracking network in the overlying gold films, preserving conductivity to high elongations (70% strain). The high sensitivity (gauge factor of 62 up to 40 % strain, and 246 from 45 – 80 % strain) of the gold sensors is unprecedented for metal film strain sensors and enabled the application of the glove sensing array for real-time gesture differentiation and robotic control. Chapter 3 comprehensively describes the electroless-nickel immersion gold metallization protocol used to fabricate the wearable strain sensing gloves.
Chapter 4 further explores variables that influence the preservation of conductivity in elastomer-supported gold films. This systematic study investigates the individual and synergistic contributions of two variables, topography and stiffness, through the fabrication and comparison of four systems that feature none, one, or both variables. The study is centered around a gold-coated layered substrate made from a stiff poly(vinyl acetate) (PVAc) topographical film on polydimethylsiloxane (PDMS), and the comparison of its electromechanical behavior to gold coatings on a planar, but compositionally analogous substrate; and a monolithic, but topographically analogous substrate. This design allows us to decouple contributions from stiffness and topography and provides insight into how the two variables work together synergistically through a mechanism of crack initiation and deflection to dramatically influence the cracking pattern and accompanying resistance change.
Chapter 5 explores the potential application of genipin as an adhesive for epidermal electronics. Genipin is a natural compound that is known to react with primary amines in skin, resulting in long-lasting, blue colouration of the epidermis. We explore the reaction between genipin and a primary amine in a skin-mimic surface, as well as on a gold film and investigate the adhesion of this gold film to the skin-mimic using genipin as an adhesive.
Chapter 6 reimagines debossed paper substrates as a way to pattern rotary-printed conductive inks. We describe a debossed contact printing (DCP) method that takes advantage of the compressibility of the pore structure of paper, which is conventionally a feature of paper that challenges the printability of functional inks. We fabricate paper-based silver, carbon-black, and poly(3,4-ethylenedioxythiophene) polystyrene sulfonate (PEDOT:PSS) electrodes, as well as silver radio-frequency identification (RFID) tags, and patterned, carbon-black, large-area electrodes for applications in smart packaging and smart homes, respectively.
Mechael, Sara, "Advanced Substrates for Wearable and Printed Electronics" (2022). Electronic Theses and Dissertations. 9010.