Aluminum has good electrical and thermal conductivity, and is used in interconnects of microcircuits and micro heat exchangers.

Copper has better conductivity than aluminum and has better ductility. Copper is an ideal material for microstructures that require high current transmission, such as coil windings in micro motors.

Gold fittings have good chemical stability and biocompatibility. When microsensors are used for biological detection or microelectrodes are used for electrochemical analysis, gold coating can prevent material corrosion and will not cause adverse reactions in biological environments.

Aluminum oxide (Al ₂ O3): It has high hardness, high melting point, and good chemical stability. In micro machining, it is used to manufacture microstructures that are resistant to high temperatures and wear. For example, in micro cutting tools, alumina ceramic tools can be used to process materials with higher hardness and maintain good cutting performance in high temperature environments.

Silicon nitride (Si ∝ N ₄): Silicon nitride has excellent mechanical properties and chemical stability. Widely used in protective films for micro mechanical seals and micro sensors. It can prevent the external environment from corroding the internal structure of the sensor, and when used as a mechanical seal, it can withstand certain pressure and be wear-resistant.

Polydimethylsiloxane (PDMS): PDMS has good flexibility and biocompatibility. It has wide applications in microfluidic chips and flexible microelectromechanical systems. For example, in microfluidic chips, PDMS can easily create microchannels through techniques such as soft lithography, and due to its flexibility, it can better bond the chip with other components.

Polymethyl methacrylate (PMMA): PMMA, also known as organic glass, has excellent optical properties and machinability. It is widely used in micro optical devices such as microlenses and micro reflectors. Through micro machining technology, PMMA can be processed into various shapes of optical structures for functions such as light focusing and reflection.

Silicon is the most commonly used material in micro machining. Because it has good mechanical properties, its hardness and strength can meet the requirements of many microstructures. Meanwhile, silicon is a semiconductor material with extensive applications in microelectronics and microelectromechanical systems (MEMS).

It can be used as an insulation layer or sacrificial layer. In micro machining, silicon dioxide is an excellent insulating material when electrical isolation is required between conductive layers. For example, when making micro capacitors, using silicon dioxide as the dielectric layer can effectively control the performance of the capacitor. As a sacrificial layer, it can be used to manufacture suspended structures through selective etching and other processes. For example, when making suspended electrodes for micro mechanical switches, after the silicon dioxide sacrificial layer is etched away, the electrodes can be suspended on the substrate.