Unique in focusing on both organic and inorganic materials from a system point of view, this text offers a complete overview of printed electronics integrated with classical silicon electronics.
Following an introduction to the topic, the book discusses the materials and processes required for printed electronics, covering conducting, semiconducting and insulating materials, as well as various substrates, such as paper and plastics. Subsequent chapters describe the various building blocks for printed electronics, while the final part describes the resulting novel applications and technologies, including wearable electronics, RFID tags and flexible circuit boards.
Suitable for a broad target group, both industrial and academic, ranging from mechanical engineers to ink developers, and from chemists to engineers.
Li-Rong Zheng is professor in Media Electronics at the Swedish Royal Institute of Technology (KTH) in Stockholm, Sweden, as well as founder and director of iPack VINN Excellence Center. Since 2010, he holds the position as a distinguished professor and director of ICT School at the Fudan University in Shanghai, China. His research interests include electronic circuits, wireless sensors, systems for ambient intelligence and the internet-of-things.
In 2001, he received his Ph.D. degree in electronic system design from the Swedish Royal Institute of Technology (KTH) in Stockholm, Sweden.
He has authored more than 400 scientific publications. He is member of the steering board of the International Conference on Internet-of-Things.
Hannu Tenhunen is professor at the Swedish Royal Institute of Technology (KTH) in Stockholm, Sweden, and holds invited and honorary professorships in Finland, USA, France, China and Hong Kong. During the last 20 years he has been actively involved in high technology policies, technology impact studies, innovations and changing the educational system. For instance, he was director of various European graduate schools and he was Education Director of the new European flagship initiative European Institute of Technology and Innovations (EIT) and the Knowledge and Innovation Community: EIT ICT Labs.
He has authored more than 700 scientific publications and holds 9 patents. Furthermore, he was one of the originators of the interconnect-centric design, globally asynchronous/locally synchronous concept and network-on-chip (NoC) paradigms.
1.1 Connected Smart World
Along with the revolution of information and communication technology () over the past decades, people have been connected to the Internet by billions of computers and mobile phones. Now this revolution is extending the connections to the physical world (things and objects), namely Internet of Things (), a vision of the connected smart world [1, 2]. It has been recognized as the third wave of the ICT industry, after the computer in the 1940s and the Internet in the 1970s. The IoT conceptually represents the future ICT world, which is often associated with such terms as "ambient intelligence," "ubiquitous computing," and "pervasive," as illustrated in Figure 1.1. Its development depends on dynamic technology evolutions in a set of multidisciplinary and interdisciplinary fields, ranging from the material and device, sensor and integration technology, to wireless communications and networking. Related technical innovations will leverage a number of emerging applications and services, which may change our lifestyle as dramatically as what has occurred since the introduction of the Internet 20 years ago.
Figure 1.1 Technologies and applications of connected smart world and the Internet of Things.
The IoT enables a wide range of applications and new business opportunities in many areas including medical and healthcare, safety and security, logistics and inventory management, manufacturing, and automation. Healthcare and intelligent logistics represent the most rapidly expanding areas where smart devices and systems can either be implanted into human or animal bodies to monitor health information or be hidden, for example, in a piece of biopaper worn on the human body or on a pharmaceutical/food package. Examples of such systems are temperature and bacteria monitoring, smart labels for food packaging, miniaturized wireless respiration monitoring devices for healthcare, radio frequency identification (RFID) systems integrated with biochemical monitoring devices for intelligent pharmaceutical packaging and storage, and large-area embedded bio-patches on flex-foil for health monitoring and analysis with radio communication links .
The IoT consists of billions of everyday objects that are being connected and smart, such as food and pharmaceutical packages, furniture, machines, wearable devices, and more. Ericsson and Cisco projected that there would be 50 billion Internet-connected devices by 2020, which is one order of magnitude greater than the 5 billion PCs and mobile phones that can be connected to the Web today (https://www.statista.com/statistics/471264/iot-number-of-connected-devices-worldwide). Such smart objects can monitor their status and the surrounding environment, as well as their geographic location. They are bridged through micropower wireless links to existing ICT infrastructures with unique identification numbers or IP addresses, allowing connections between the virtual world of the Internet and the physical world of things.
1.2 Smart Electronic Systems
Smart systems (s) usually combine cognitive functions with sensing, actuation, data communication, and energy management in an integrated way to provide safe and reliable autonomous operation under all relevant circumstances. Depending on the degree of autonomy, smart systems are categorized into three generations .
- First generation smart systems integrate sensing and/or actuation as well as signal processing to enable actions.
- Second generation smart systems are built on multifunctional perception and are predictive and adaptive systems with self-test capabilities that are able to match critical environments. Moreover, they are equipped with network facilities and advanced energy scavenging and management capabilities
- Third generation smart systems perform human-like perception and autonomy, and are able to generate energy.
Smartness or intelligence presented above is essentially realized by Smart Electronic Systems seamlessly integrated with everyday objects that can be physically flexible. Such systems usually incorporate functions of sensing/actuating, computing/perception, and communication and networking. A generic architecture along with typical building blocks of a smart electronic system is illustrated in Figure 1.2. It consists of an embedded processor and memories, a radio for wireless networking, energy harvesting, and storage, sensors/actuators, and interface circuits that interact with the environment or people. Thanks to the heterogeneous nature, the development of smart electronic systems requires joint efforts in two dimensions as depicted in Figure 1.3: (i) evolution of the semiconductor technology driven by Moore's law and beyond ("More Moore"); (ii) multifunctionality and diversity that are enabled by emerging technologies with different materials and devices, the so-called "More-than-Moore" . On the one hand, integrated circuits (s) have been scaling along the trend of "More Moore" toward sub-10?nm, offering increased density and lower power consumption with reduction in cost per transistor and cost per function . On the other hand, interfacing to the real world and to the human body and senses requires that electronics or other functional devices are distributed over a large surface area. There is therefore a great demand for electronic devices and systems on the macroscale, the so-called macroelectronics  or large-area electronics (s) , aiming to decrease the cost per area . Initially, the LAE (including printed, flexible, or organic electronics) was driven by area-intensive applications, such as displays and photovoltaics. Then, the application scope has expanded dramatically over recent decades, covering medical, sensing, flexible, and ultrathin consumer devices, pursuing cheaper electronics capable of interacting with the environment on the macroscale . The development of flexible and printed electronics (s) enables the cost-effective manufacture of such devices.
Figure 1.2 Architecture and main building blocks of a smart electronic system.
Figure 1.3 Technology roadmap of smart electronic systems in the ear of "More Moore" and "More-than-Moore."
Smart electronic systems are targeted to provide adequate performance, but in a low cost, novel form factor on flexible substrates such as paper or stretchable plastic. Printing as a manufacturing technique is a promising approach to fabricate low-cost, flexible, and LAEs on flexible media, including circuits, sensors, antennas, transducers, and batteries. Compared with silicon-based circuits (more specifically, CMOS ICs), all-printed systems yet suffer from low integration density, long switching time, and high cost per function. For example, the speed and energy efficiency of the state-of-the-art thin-film transistors (s) remain orders of magnitude below the complementary metal-oxide semiconductor () technology. Therefore, silicon-based chips performing sophisticated feats such as communication computation and communication are still inevitable. Thus, a heterogeneous integration platform for hybrid systems is in great demand, which employs a cost-effective, large-area manufacturing technique while keeping the same complex functionality and processing capability as silicon-based systems. The complementariness of silicon-based electronics (CMOS) and printed electronics (LAE) are summarized in Table 1.1 .
Table 1.1 Complementariness of silicon electronics and printed electronics. CMOS LAE
Computation High throughput Low speed High logic density Low logic density Low energy/MHz Communication High data rate Coupling Low energy/bit Interconnects Large-size antenna Sensing Precision instrumentation Transducers Analog-information convertors Large substrates Power DC-DC/AC-DC conversion Energy harvester Regulators Printed battery Adaptive management
1.3 Overview of the Book
To realize the vision of the IoT toward a truly connected smart world, there are three key enablers in smart electronic system design. (i) Self-powered integrated circuits based on advanced CMOS technology for computing, communication, sensing, and perception; (ii) flexible and LAEs for multifunctionality and interfacing to the analogy; and (iii)...