Miniaturization has been a technological trend for several decades for electronic devices. From the practical point of view, the successful miniaturization of fully integrated systems mainly depends on their components. This dissertation examines the inkjet printing of copper oxide inks on flexible substrates for applications in microfluidic valving systems. We expand the knowledge of low-cost and high-performance electrowetting valves and fabricate the microfluidic device for fluidic control, which is necessary to enable the next-generation microfluidic devices. In addition, we also study the electromagnetic interference (EMI) shielding material, which is a crucial part of electronic devices. The basic theory of EMI shielding is discussed in this dissertation. We explore the high-performance shielding materials with novel fabrication methods, such as spray coating, laser carbonizing and electroplating. Chapter 1 describes the fabrication of flexible inkjet-printed copper electrowetting valves. We study the effects of dielectric layer thickness as well as applied voltage to the contact angle decreasing process. Taking this one step further, an electrowetting valve with two controlled channels is described for demonstration. Chapter 2 explores the fabrication of high-performance EMI shielding material of silver-coated carbon fiber fabrics (CFFs) via spray coating. EMI shielding theory is discussed in detail. The silver/CFF composite material is introduced at the lab-scale as well as at the roll-to-roll large fabrication scale. Chapter 3 introduces the high-performance optically transparent copper mesh. The laser carbonizing and electroplating techniques are described. We study the effect of different patterns to the EMI shielding performance. Chapter 4 evaluates the EMI shielding performance of graphite/polymer composites. Microwave exfoliation and acid treatment are explained from the mechanism aspect. Furthermore, future work is described for potential improvement on their performance.