Bioinspired Engineering of Thermal Materials

Tao Deng

• Publisher: Wiley-VCH
• Year: 2018
• Print ISBN: 9783527338344
• eBook ISBN: 9783527687619
• Edition: 1
• Topic: Technology & Engineering
• Subtopic: Materials Science
• Index: Technology & Engineering

A comprehensive overview and summary of recent achievements and the latest trends in bioinspired thermal materials.
Following an introduction to different thermal materials and their effective heat transfer to other materials, the text discusses heat detection materials that are inspired by biological systems, such as fire beetles and butterflies. There then follow descriptions of materials with thermal management functionality, including those for evaporation and condensation, heat transfer and thermal insulation materials, as modeled on snake skins, polar bears and fire-resistant trees. A discussion of thermoresponsive materials with thermally switchable surfaces and controllable nanochannels as well as those with high thermal conductivity and piezoelectric sensors is rounded off by a look toward future trends in the bioinspired engineering of thermal materials.
Straightforward and well structured, this is an essential reference for newcomers as well as experienced researchers in this exciting field.

Chapter 1
Introduction to Thermal Properties of Materials

Rui Feng and Chengyi Song

State Key Laboratory of Metal Matrix Composites, School of Materials Science and Engineering, Shanghai Jiao Tong University, 800 Dongchuan Road, Shanghai, 200240, P. R. China

This introductory chapter encompasses the basic principles and calculation methods for the heat transfer process and the advanced thermal properties. Various thermal applications of bioinspired functional materials will also be briefly discussed. To elucidate the basic principles of thermal theory, several analytical examples involving heat source and boundary conditions, uniform and nonuniform mesh structures, multiphase transfer, phase change, and convection in fluidic cases are also described. Noticing that micro/nanoscale materials exhibit unique thermal properties in modern materials scientific research, in this chapter the new developments in micro/nanoscale heat transfer theory are also discussed and some of the theoretic solutions drawn in calculating the thermal conductivity of micro/nanomaterials are shown. Biological systems set numerous examples in teaching humans how to collect, convert, and harness thermal energy from nature. In the last section of this chapter, practical approaches are discussed in an overview of bioinspired thermal materials. Typical thermal applications of functional materials (e.g., thermal nanofluids such as nanosuspension of colloidal particles in solution, the rapid charging of thermal energy storage, the phase change energy conversion by photothermal membrane, and the sensing of infrared radiation by bioinspired materials) are presented to show how the modern conventional and micro/nano heat transfer theory is related to advanced thermal functions of bioinspired materials.

1.1 Conventional Macroscale Heat Transfer

Heat transfer forms a vital kinetic force in the maintenance of the basic energy operation of the whole natural system for the activities of all the creatures on earth. As an engineering discipline, the inherent laws of heat transfer do not merely explain the way of energy transportation but also deal with the thermodynamics of both objects and the equilibrium principle under specified conditions. Fundamental learning of the equilibrium principle is provided by the first and second laws of thermodynamics, and follows the classic mechanics of conduction, convection, and radiation. In the following sections, the conduction, convection, and radiation of macroscale heat transfer problems will be shown and the working principles formulated by energy equations. In thermal physics and engineering problems, we use critical quantitative criteria to characterize the thermal properties of material. These thermal properties are modified as representations of thermal energy transportation and energy conservation models, and can be used to analytically or numerically solve problems in thermal engineering and nature. Therefore, in the following sections, the basic principles of thermal transfer will be introduced first through a discussion of the thermal energy transportation and energy conservation models.

1.1.1 Normalization

To describe the process of heat transfer based on quantitative criteria, the primary quantities involved in a thermal process are listed in Table 1.1 and the quantitative criteria of thermal process are derived by these basic units. For analyzing much more complicated situations, the units of some derived quantities in Table 1.2 are defined as scientific descriptions of thermal properties of materials. Especially in numerical calculations and study of material heat transfer models, these derived units such as specific heat capacity C_p, thermal conductivity κ, heat flux q and thermal diffusivity α in thermodynamics cases will facilitate the systematic learning and understanding of the details of heat transfer.

Table 1.1 Basic parameter units

Primary quantity	Parameter
Length	L (m)
Time	t (s)
Mass	m (kg)
Temperature	T (°C or K)
Current	Je (A)

Table 1.2 Parameter units driven by the primary quantities in Table 1.1

Driven quantity	Parameter
Specific heat capacity	Cp (J/kg K)
Energy	E (J or N m)
Force	F (N m/s^2)
Electric charge	C (coulomb or A s)
Thermal conductivity	k (W/m k)
Pressure	p (Pa or N/m^2)
Heat flux	q (W/m^2)
Heat efficiency	Q (W or J/s)
Velocity	V (m/s)
Viscosity	μ (Pa s)
Density	A ρ (kg/m^3)
Potential	Φ (V or W/A or J/C)

In developing and judging thermal properties of new materials, normalizing the units of critical parameters may help us to better learn and understand different thermal properties.

1.1.2 Thermal Equilibrium and Nonequilibrium

Thermal equilibrium and nonequilibrium are the descriptions of the energy state of a thermal system. In an isolated steady thermal system, the state of thermal equilibrium will become stable without any external energy input. Once higher/lower temperature occurs at a specific point of the system, local thermal nonequilibrium exists. Meanwhile, the temperature difference will force the thermal energy to be transported from a region with higher temperature to a region with lower temperature. The system will eventually be in an equilibrium state after a spontaneous transformation process. The process of turning nonequilibrium into equilibrium is dominated by temperature difference. The gradient of temperature difference triggers heat diffusion, which can be ascribed to thermal conduction, thermal convection, and thermal radiation. Howeve...

Table of contents

• Cover
• Title Page
• Copyright
• Table of Contents
• Chapter 1: Introduction to Thermal Properties of Materials
• Chapter 2: The Engineering History of Thermal Materials
• Chapter 3: Bioinspired Surfaces for Enhanced Boiling
• Chapter 4: Bioinspired Materials in Evaporation
• Chapter 5: Bioinspired Engineering of Photothermal Materials
• Chapter 6: Bioinspired Microfluidic Cooling
• Chapter 7: Thermal Emissivity: Basics, Measurement, and Biological Examples
• Chapter 8: Bioinspired Thermal Detection
• Chapter 9: Bioinspired Thermal Insulation and Storage Materials
• Chapter 10: Bioinspired Icephobicity
• Index
• End User License Agreement