Transfer printing and thermal shape-morphing technology based on membrane-type electronics and plastic-elastomer frameworks

Abstract

As the evolution of electronics, communication, and artificial intelligence (AI) advances the interaction between human and machine, society rapidly relies on autonomous systems for environment monitoring (space, marine, etc.), surveillance systems, biomedical devices, and autopilot systems (aircraft, vehicle). To attain such systems, the device should guarantee high performance, high spatial resolution, and omnidirectional of the sensory part, and reliable three-dimensional (3D) shape morphing. Even though the examples of developing membrane-type electronics and 3D electronics based on additional supportive frameworks have been introduced, process temperature and developable shapes seem to be limited to Tg of the thermoplastics and zero Gaussian curvature, respectively, due to the intrinsic properties of the substrate materials. To overcome such limitations, this thesis aims to introduce two methodologies: 1) means of transfer printing fragile inorganic substrate that can endure extreme temperatures and 2) shape-morphing technology with a plastic-elastomer framework that can envision the pathway to realize complex 3D electronics with both zero and non-zero Gaussian curvatures. In particular, this thesis is composed of three chapters. Chapter 1 overviews transfer printing techniques of membrane-type electronics and shape-morphing technology that can be implemented to develop novel 3D electronics. In PhD/MS 20152030 ii particular, this chapter introduces printable prints to realize membrane-type electronics on unusual surfaces and transformation technologies using various plastics and elastomers to form unconventional 3D structures. Furthermore, this chapter shares the feasibility of combining transfer printing and transformation technologies to realize complex 3D electronics. Chapter 2 examines the reliable methodology of transferring thermally stable and transparent ultrathin silicon dioxide (SiO2) substrate. The challenging issue of this method is retrieving and delivering the mechanically brittle SiO2 substrate from the donor to the unusual target surfaces in a deterministic and stable manner. In this study, a layer of SU-8 and periphery anchors are employed on the SiO2 substrates to retrieve the SiO2 substrate from the donor and print it on the polymeric substrate. Moreover, a design of corners of SiO2 substrate and following numerical simulation results shows the prevention of any crack formation. To confirm the feasibility of this method, indium gallium zinc oxide (IGZO)-based inverter and logic gates were developed on SiO2 substrate and transferred onto the polymeric substrate. Chapter 3 deals with the strategy to develop complex 3D electronics based on the combination of IGZO-based membrane-type electronics and the shape-morphing framework. The key idea of this study is to create facile means of securing interfacial adhesion between each layer; in this case: device (IGZO), damping (Ecolfex), and shape-morphing (ABS) layers. The introduction of self-assembled monolayers (SAM) attains strong interfacial adhesion without hampering any flexibility. Moreover, this methodology allows degree-of-freedom to position stressed ABS lines to realize complex 3D structures with zero or even non-zero Gaussian curvatures. To prove this approach, bonding of printable IGZO-based transistor arrays and plastic-elastomer framework and transformation allows 3D shaped IGZO transistor arrays.