Introduction of Sapphire Capillary Tubes

Sapphire Capillary Tubes are high-precision hollow microstructures fabricated from synthetic single-crystal sapphire (Al₂O₃), renowned for their extreme hardness (Mohs 9), excellent thermal stability, broad optical transmission range, and outstanding chemical resistance. These tubes are available in a wide range of sizes, including straight, tapered, or custom-bent forms, with inner diameters as small as 0.1 mm and wall thicknesses as low as 0.05 mm. Thanks to sapphire’s high structural strength and biocompatibility, Sapphire Capillary Tubes can withstand extreme environments where glass, quartz, or polymer tubes would fail—making them ideal for high-temperature, high-pressure, or highly reactive applications.

Depending on end-use, the internal surface of Sapphire Capillary Tubes can be fine-ground or optically polished to meet requirements for fluidic smoothness, minimal adsorption, or efficient light transmission. These tubes are widely applied in laser optics, medical diagnostics, semiconductor processing, and analytical chemistry, as well as in aerospace and petrochemical systems. Compared to conventional capillary materials, Sapphire Capillary Tubes offer significantly longer service life, lower contamination risk, and superior performance under mechanical or thermal stress, making them a preferred choice for precision-critical and mission-critical applications.

Manufacturing Principle of Sapphire Capillary Tubes

The production of Sapphire Capillary Tubes is based on two main crystal growth techniques: the Kyropoulos method (KY) and the Edge-defined Film-fed Growth (EFG) method.

The KY method begins by melting high-purity aluminum oxide in a crucible and slowly growing a large, optically clear single-crystal sapphire boule. This boule is then oriented, sliced, and cored using diamond tools or ultrasonic drilling to produce a hollow channel. The outer and inner surfaces are subsequently ground and polished to achieve high surface quality and dimensional accuracy. This method is ideal for producing capillary tubes with excellent optical performance and ultra-smooth internal bores, widely used in lasers, medical diagnostics, and precision analysis.

The EFG method, on the other hand, allows direct growth of hollow sapphire tubes through a shaped

die. In this process, molten sapphire material is drawn upward through a capillary mold, forming a tube in a continuous manner. While surface roughness may be higher compared to KY-grown tubes, EFG tubes require less post-processing and are more cost-effective for industrial-scale production. They are particularly suited for technical applications such as gas sampling, protective sheaths, or thermal fluid systems.

Regardless of the growth method, all Sapphire Capillary Tubes undergo strict machining, internal polishing, ultrasonic cleaning, and inspection. The final result is a product with high dimensional precision, excellent inner wall quality, and reliable performance even in the most extreme environments.

Sapphire Capillary Tube Specifications

Applications of Sapphire Capillary Tubes

Sapphire Capillary Tubes are trusted in a variety of high-tech fields due to their robust physical and chemical properties:

• Medical and Biological Diagnostics
  Used in microfluidic chips, DNA sequencing devices, and blood analyzers. Their non-reactive nature ensures accurate and sterile fluid delivery for sensitive biological samples.

• Laser and Optical Systems
  Employed as optical sleeves, beam guides, or protective housings for fiber optics. Thanks to sapphire’s broad-spectrum transparency (200 nm – 5000 nm), they enable stable optical transmission in spectroscopy, LIDAR, and photonics.

• Semiconductor and Electronics Industry
  Used to transport gases or liquids in plasma etching chambers, CVD reactors, and vacuum systems. Sapphire's resistance to high temperatures and corrosive chemicals ensures system purity and longevity.

• Chemical Analysis and Chromatography
  Instruments like HPLC and GC benefit from the ultra-smooth internal surfaces of Sapphire Capillary Tubes, which prevent sample adsorption and support trace-level detection.

• Aerospace and Defense
  Integrated into high-vibration, high-temperature systems for fluid regulation, optical sensing, or protective shielding. They maintain structural integrity even under harsh operating conditions.

• Energy and Petrochemical Fields
  Suitable for high-pressure fluid lines, fuel cell systems, and corrosive gas sampling. Their thermal and chemical resistance makes them ideal for aggressive industrial environments.

FAQ – Frequently Asked Questions of Sapphire Capillary Tubes

Q1: What material are Sapphire Capillary Tubes made from?
A: They are made from 99.99% pure single-crystal aluminum oxide (Al₂O₃), known as sapphire, which is second only to diamond in hardness.

Q2: What size range is available for inner and outer diameters?
A: Standard Sapphire Capillary Tubes range from 0.1 mm to 3.0 mm inner diameter, with outer diameters up to 10 mm or more. Custom sizes are available upon request.

Q3: Can the inner bore be optically polished?
A: Yes. Depending on the application, the bore can be ground or optically polished to reduce friction, improve light transmission, or minimize residue buildup.

Q4: Are Sapphire Capillary Tubes safe for biomedical use?
A: Absolutely. They are biocompatible, non-toxic, and resistant to all standard sterilization methods, making them ideal for clinical and laboratory environments.

Q5: How are Sapphire Capillary Tubes cleaned and packaged?
A: Tubes are cleaned using ultrasonic methods in deionized water and solvents, then packed in cleanroom-compatible containers to prevent contamination.

Q6: Do you offer customization for specific projects?
A: Yes. We offer full customization in terms of length, bore diameter, wall thickness, surface finish, and even flanged or tapered ends based on customer drawings or specifications.

Q7: What industries use Sapphire Capillary Tubes the most?
A: Common users include medical device manufacturers, laser system integrators, semiconductor fabs, research labs, and aerospace equipment suppliers.

Related Products

Sapphire tube EFG double side polish for Laser and Optical Systems

High Purity Sapphire Tube With Extreme Heat Resistance 99 995% Length 1-1500mm EFG Technology

About Us

ZMSH specializes in high-tech development, production, and sales of special optical glass and new crystal materials. Our products serve optical electronics, consumer electronics, and the military. We offer Sapphire optical components, mobile phone lens covers, Ceramics, LT, Silicon Carbide SIC, Quartz, and semiconductor crystal wafers. With skilled expertise and cutting-edge equipment, we excel in non-standard product processing, aiming to be a leading optoelectronic materials high-tech enterprise.

Packaging & Shipping Information

Packaging Method:

• All items are securely packed to ensure safe transit.
• Packaging features anti-static, shock-resistant, and dust-proof materials.
• For sensitive components such as wafers or optical parts, we adopt cleanroom-level packaging:

1. Class 100 or Class 1000 dust protection, depending on product sensitivity.
2. Customized packaging options are available for special requirements.

Shipping Channels & Estimated Delivery Time:

• We work with trusted international logistics providers, including:

UPS, FedEx, DHL

• Standard lead time is 3–7 business days depending on the destination.
• Tracking information will be provided once the order is dispatched.
• Expedited shipping and insurance options are available upon request.