The fundamental principles of electronic device and circuit design are discussed in a clear and detailed manner along with explanatory diagrams. Various IoT-based smart applications in different fields along with challenges and issues along with prospects of IoT for future applications have also been discussed. The chapters delve into myriad aspects of circuit design, including MOSFET structures depending on their low power applications for IoT-enabled systems, advanced sensor design and fabrication using MEMS, indirect bootstrap techniques, efficient CMOS comparators, various encryption-decryption algorithms, IoT video forensics applications, microstrip patch antennas in embedded IoT applications, real-time object detection using sound, IOT and nanotechnologies based wireless sensors, and much more. It also introduces logic BIST using BS-CFSR for electronic devices that can be part of many applications in many industries, such as defense, automotive, banking, computer, healthcare, networking, and telecommunication.