The main components of the micro air pump include diaphragm, piston, valve, seal, gas path and housing. Each part has different performance requirements for the material.
(1) Diaphragm
Performance requirements: high elasticity, fatigue resistance, good air tightness, chemical corrosion resistance.
Recommended materials:
Silicone Rubber: Good flexibility, high temperature resistance (above 200°C), strong chemical inertness, suitable for medical grade applications.
Fluororubber (Viton/FKM) : Excellent wear and oil resistance, suitable for long-term operation.
Polytetrafluoroethylene (PTFE) coating: Adding a PTFE coating to the surface of the diaphragm enhances chemical resistance and air tightness while reducing friction.
(2) Piston
Performance requirements: high hardness, low friction, strong wear resistance, dimensional stability.
Recommended materials:
Ceramic materials, such as alumina or zirconia ceramics, have extremely high hardness and wear resistance, while the coefficient of friction is low, suitable for long-term operation.
Engineering Plastics (POM/PEEK) :
POM (polyformaldehyde) : Low friction coefficient, good dimensional stability, suitable for low to medium load applications.
PEEK (polyether ether ketone) : high temperature and corrosion resistance, suitable for high-intensity scenarios.
Metal materials:
Stainless steel (e.g. 316L) : Excellent corrosion resistance, suitable for medical grade high strength scenarios.
Aluminum alloy: Light weight, suitable for portable devices, but need to be coated with anti-oxidation coating.
(3) Valves
Performance requirements: high responsiveness, wear resistance, fatigue resistance, sealing.
Recommended materials:
Silicone or fluoro rubber: High flexibility, suitable for valve disc applications, ensuring fast response.
PEEK or polytetrafluoroethylene (PTFE) : Resistant to chemical corrosion and high temperatures, for precision spool.
Metal material (stainless steel or titanium alloy) : suitable for high precision, high strength valve body.
(4) Seals
Performance requirements: strong air tightness, wear resistance, chemical corrosion resistance, long life.
Recommended materials:
Fluororubber (FKM/Viton) : suitable for high temperature and high pressure environments.
EPDM (EPDM) : has excellent aging resistance and chemical inertness, suitable for contact with oxygen.
Medical grade silicone: soft, chemically inert.
(5) Gas routes and pipelines
Performance requirements: chemical resistance, smooth inner wall, low gas resistance, health and safety.
Recommended materials:
Polyethylene (PE)/polypropylene (PP) : lightweight, strong chemical resistance.
Polyurethane (PU) : Soft and suitable for bending pipes.
Stainless steel or aluminum alloy: for high strength or high pressure gas lines.
(6) Shell
Performance requirements: impact resistance, corrosion resistance, sound insulation, high and low temperature resistance.
Recommended materials:
High-performance plastics (such as ABS or PC-ABS alloys) : Good impact resistance and suitable for lightweight designs.
Aluminum alloy: Light weight, good heat dissipation.
Stainless steel: Suitable for high-strength applications, but relatively heavy in weight.
2. Key performance and material matching
(1) High wear resistance
Material Solutions:
Piston parts are made of ceramic or high-performance engineering plastics such as PEEK.
The valve uses high elastic fluorine rubber to reduce the wear of the valve disc and seat.
(2) Air tightness
Material Solutions:
Use materials with low gas permeability (such as PTFE-coated diaphragms or fluororubber seals).
Ensure machining accuracy and material surface treatment to reduce gas leakage.
(3) Chemical corrosion resistance
Material Solutions:
Silicone, fluororubber, PTFE and other materials are used for parts that come into contact with cleaners and disinfectants.
Use corrosion-resistant metals (such as 316L stainless steel or titanium alloy) for piston and valve body components.
(4) Biological compatibility
Material Solutions:
All materials in contact with the gas must be medically certified (e.g. USP Class VI).
Ensure that the surface of the material is free of harmful precipitates, suitable for long-term contact with the patient's breathing gas.
3. Application of advanced material technology
(1) Coating technology
Low friction coating: Coating PTFE or DLC (diamond-like coating) on the surface of key components such as pistons and diaphragms to reduce friction and improve life.
Antibacterial coating: Antibacterial coating can be added to the shell or gas path material to reduce the risk of pathogen transmission.
(2) Composite materials
Use of multilayer composite structures in diaphragms and seals:
** Inner flexible material (e.g. silicone) ** provides elasticity.
** Outer layer of high strength material (such as nylon fiber) ** enhanced durability.
4. Material testing and verification
(1) Performance test
High and low temperature test: to ensure that the material performance is stable within -20°C to 50°C.
Air tightness test: Detect the gas leakage of diaphragm and seal under high pressure.
(2) Life test
Fatigue test: Simulate long-term operating conditions to verify the fatigue resistance of materials.
Chemical testing: Assessing the stability of materials in different disinfectant environments.
(3) Medical certification
The material must pass the ISO 10993 biocompatibility test to ensure that it is not harmful to humans.