The Tsinghua University–University of Waterloo Joint Research Center for Micro/Nano Energy & Environment Technology (JCMEET) is a platform. It was established on Nov.11, 2017. The Chairperson of University Council of Tsinghua University, Dr. Xu Chen, and the President of the University of Waterloo, Dr. Feridun Hamdullahpur, attended the opening ceremony and unveiled the nameplate for the joint research center on 29th of March, 2018. The research center serves as a platform for researchers at both universities to conduct joint research in the targeted areas, and to meet regularly for information exchange, talent exchange, and knowledge mobilization, especially in the fields of micro/nano, energy, and environmental technologies. The center focuses on three main interests: micro/nano energy technology, micro/nano pollution control technology, and relevant fundamental research. In order to celebrate the first anniversary of the Joint Research Center, we were invited to serve as the Guest Editors of this Special Issue of Materials focusing on the topic of micro/nano-materials for clean energy and environment. It collects research papers from a broad range of topics related to micro/nanostructured materials aimed at future energy resources, low emission energy conversion, energy storage, energy efficiency improvement, air emission control, air monitoring, air cleaning, and many other related applications. This Special Issue provides an opportunity and example for the international community to discuss how to actively address the energy and environment issues that we are facing.

Humidity is the presence of water vapor in the air. In view of its effect on human health and the physical qualities of materials, humidity must be measured and controlled. Humidity measurement is imperative in a variety of fields including health care, environmental monitoring, automobiles, air-conditioning, civil engineering, agriculture, semiconductors, pharmaceuticals, textiles, paper and processing industries. This book provides an overview of humidity and the types and applications of humidity sensors. This book will be helpful for students, researchers and general readers.

The first volume of The Handbook of Humidity Measurement focuses on the review of devices based on optical principles of measurement such as optical UV, fluorescence hygrometers, optical and fiber-optic sensors of various types. Numerous methods for monitoring the atmosphere have been developed in recent years, based on measuring the absorption of electromagnetic field in different spectral ranges. These methods, covering the optical (FTIR and Lidar techniques), as well as a microwave and THz ranges are discussed in detail in this volume. The role of humidity-sensitive materials in optical and fiber-optic sensors is also detailed. This volume describes the reasons for controlling the humidity, features of water and water vapors, and units used for humidity measurement.

Because of unique water properties, humidity affects materials and many living organisms, including humans. Humidity control is important in various fields, from production management to creating a comfortable living environment. The range of materials that can be used in the development of humidity sensors is very broad, and the third volume of the Handbook of Humidity Measurement offers an analysis on various humidity-sensitive materials and sensor technologies used in the fabrication of humidity sensors and methods acceptable for their testing. Additional features include: numerous strategies for the fabrication and characterization of humidity-sensitive materials and sensing structures used in sensor applications, methods and properties to develop smaller, cheaper, more robust, and accurate devices with better sensitivity and stability, a guide to sensor selection and an overview of the humidity sensor market, and new technology solutions for integration, miniaturization, and specificity of the humidity sensor calibration. Handbook of Humidity Measurement, Volume 3: Sensing Materials and Technologies provides valuable information for practicing engineers, measurement experts, laboratory technicians, project managers in industries and national laboratories, and university students and professors interested in solutions to humidity measurement tasks. Despite the fact that this book is devoted to the humidity sensors, it can be used as a basis for understanding fundamentals of any gas sensor operation and development.

Because of unique water properties, humidity affects many living organisms, including humans and materials. Humidity control is important in various fields, from production management to creating a comfortable living environment. The second volume of The Handbook of Humidity Measurement is entirely devoted to the consideration of different types of solid-state devices developed for humidity measurement. This volume discusses the advantages and disadvantages about the capacitive, resistive, gravimetric, hygrometric, field ionization, microwave, Schottky barrier, Kelvin probe, field-effect transistor, solid-state electrochemical, and thermal conductivity-based humidity sensors. Additional features include: Provides a comprehensive analysis of the properties of humidity-sensitive materials, used for the development of such devices. Describes numerous strategies for the fabrication and characterization of humidity sensitive materials and sensing structures used in sensor applications. Explores new approaches proposed for the development of humidity sensors. Considers conventional devices such as phsychometers, gravimetric, mechanical (hair), electrolytic, child mirror hygrometers, etc., which were used for the measurement of humidity for several centuries. Handbook of Humidity Measurement, Volume 2: Electronic and Electrical Humidity Sensors provides valuable information for practicing engineers, measurement experts, laboratory technicians, project managers in industries and national laboratories, as well as university students and professors interested in solutions to humidity measurement tasks as well as in understanding fundamentals of any gas sensor operation and development.

Relative humidity is a term used to describe the amount of water vapour that exists in a gaseous mixture of air and water vapour. The relative humidity of an air-water mixture is defined as the ratio of the partial pressure of water vapour in the mixture to the saturated vapour pressure of water at a prescribed temperature. This book presents current research in the study of relative humidity, including humidity-sensitive and non-ohmic tin dioxide ceramics; optics of airborne particles under elevated humidity conditions; a review of relative humidity management and its environmental effects; relative humidity effects in a spa; and relative humidity modelled by a functional network.

Because of unique water properties, humidity affects materials and many living organisms, including humans. Humidity control is important in various fields, from production management to creating a comfortable living environment. The range of materials that can be used in the development of humidity sensors is very broad, and the third volume of the Handbook of Humidity Measurement offers an analysis on various humidity-sensitive materials and sensor technologies used in the fabrication of humidity sensors and methods acceptable for their testing. Additional features include:  numerous strategies for the fabrication and characterization of humidity-sensitive materials and sensing structures used in sensor applications,  methods and properties to develop smaller, cheaper, more robust, and accurate devices with better sensitivity and stability,  a guide to sensor selection and an overview of the humidity sensor market, and  new technology solutions for integration, miniaturization, and specificity of the humidity sensor calibration. Handbook of Humidity Measurement, Volume 3: Sensing Materials and Technologies provides valuable information for practicing engineers, measurement experts, laboratory technicians, project managers in industries and national laboratories, and university students and professors interested in solutions to humidity measurement tasks. Despite the fact that this book is devoted to the humidity sensors, it can be used as a basis for understanding fundamentals of any gas sensor operation and development.