Polymers are a type of substance composed of small repetitive chemical units. The synthetic blocks or repeating units in polymers are called monomers. Polymerization or polymer synthesis is a chemical reaction in which monomers are covalently bonded together to form a polymer structure. The length of a polymer chain is expressed by the number of repeating units in the chain, which is called the degree of polymerization (DP). The molecular weight of a polymer is the product of the repeated unit molecular weight and DP. The inherent basic characteristics of polymers mainly depend on their molecular weight, structure (straight or branched), and DP.

According to the types of chemical reactions involved, polymerization can be divided into two categories, namely condensation polymerization and addition polymerization. In condensation polymerization or stepwise growth polymerization, a condensation reaction occurs between two different bifunctional or trifunctional monomers, producing a polymer that eliminates small molecules (usually water) in the reaction. In addition polymerization or chain growth polymerization, polymer growth is achieved by adding monomers to the active sites at the end of the polymer chain and returning to the active sites after each growth step is completed. An initiator is required to produce an initiator substance with a reaction center. The reaction center can be a free radical, cation, anion, or organometallic complex.

Bioelectronics is an interdisciplinary field that combines biology and electronics, and can be used for diagnostic and therapeutic healthcare applications. By utilizing bioelectronic technologies that influence specific molecular processes in neural signal transduction, the regulatory activity of the nervous system can be monitored and controlled. Bioelectronic medicine deals with a series of diseases and obstacles, such as blindness, cardiovascular diseases, diabetes, inflammatory and neurodegenerative diseases and paralysis. Bioelectronic devices work by stimulating, regulating, or blocking specific electronic communication signals between the brain and functional organs of the body, thereby achieving personalized treatment. Common biomedical devices include pacemakers that regulate heart rate and robotic prosthetics that mimic the human environment. Biosensors such as blood glucose monitors can detect enzymes, pathogens, or toxic substances. Wearable bioelectronic devices can monitor vital signs, detect biomarkers, or capture epidermal energy. Advanced bioelectronic implants can work without wires or batteries, and according to different applications, they have the characteristics of minimal invasiveness, digestibility, and complete absorption.

Micron particles and nanoparticles, as unique materials, have enormous potential for application in fields such as energy, healthcare, and the environment. Nanoparticles refer to particles with at least one physical dimension smaller than 100 nanometers. Micron particles refer to particles with a physical dimension ranging from 1 to 1000 micrometers. Although they have the same composition in macroscopic materials, the two types of particles have different optical, electrical, thermal, and magnetic properties due to size effects. Researchers have developed various methods for synthesizing two types of particles to better control their properties, shape, composition, and size distribution that are suitable for specific fields Usually, physical and chemical methods are used for synthesis. Physical methods synthesize particles by reducing the size of raw materials, which is known as a top-down approach. Usually, physical technologies such as ball milling, gas condensation, electrospray, lithography, and thermal decomposition are required. In many chemical methods, particles are usually synthesized by nucleation and growth of atomic or molecular precursors in liquid or gas phase chemical reactions, which is known as a bottom-up approach. Microemulsion method, hydrothermal method, microfluidic method, chemical vapor deposition, pyrolysis method and sol gel method are commonly used chemical synthesis methods. The nanostructures synthesized by chemical synthesis have fewer defects, allowing for more complex and uniform chemical composition. Moreover, due to their ease of expansion, the synthesized production cost is low and the speed is fast.

Solid state synthesis, also known as ceramic synthesis, is commonly used to initiate chemical reactions in solid starting materials, thereby forming new solids with regular structures. The final products include polycrystalline materials, monocrystalline materials, glass, and thin film materials widely used in energy and electronic applications. Under controlled temperature, fine metal compounds are combined with each other, then granulated and heated for a period of time. Some metal compounds (such as metal oxides or salts) require extreme conditions such as high temperature and high pressure to initiate reactions in the melt or rapidly condensing vapor phase. This process is often referred to as "shaking and baking" or "heating and striking" chemistry The reaction rate in solid-state synthesis is a particularly important characterization parameter. Due to the limited purification technology for the formed solid, the solid-state reaction must be complete. The reaction rate of solid-state reactions depends on the reaction conditions, including structural characteristics, shape and surface area of reactants, diffusion rate, and thermodynamic properties related to nucleation/reaction. The physical and chemical properties of the final material depend on the chemical precursors and preparation techniques.