This book provides readers with an overview of kinetic energy harvesting systems, their applications, and a detailed discussion of circuit design of variable-capacitance electrostatic harvesters. The authors describe challenges that need to be overcome when designing miniaturized kinetic energy harvesting systems, along with practical design considerations demonstrated through case studies of developing electrostatic energy harvesting systems. The book also,Discusses the subject of Miniaturized Variable-Capacitance Electrostatic Energy Harvesters from both a theoretical and practical/experimental point of view. Describes detailed circuit designs for developing miniaturized electrostatic harvesters. Includes a comprehensive comparison framework for evaluating electrostatic harvesters, enabling readers to select which harvesters are best suited for a particular application.