Micro Star Bore Capillary Glass Tubing

Micro Star Bore Capillary Glass Tubing

The micro Starbore capillary decreases the pressure drop necessary to produce a specified flow rate by reducing the area of contact between the fluid and the capillary wall. The inability of water to wet glass crevices which are the size of the micro Starbore points at the pulled tip (about 1.4u wide.) is well known. This principle is responsible for the improved filling characteristics of a fiber-filled capillary. The partial adherence of the glass fiber to capillary wall creates two sharp corners which do not wet when the tube is filled, decreasing the wetted surface contact area.

The micro Starbore capillary takes this principle to the ultimate by creating the ideal geometry for micro pipette electrodes eliminating the need for fiber addition. As fluid is injected into the capillary, it fills the center of the “star” trapping air in the star’s five points. At the pulled tip of the capillary, surface tension causes the exiting liquid to spread over the tip of the micro pipette electrode, sealing the air in the points of the star.

Since the liquid will not wet the points of the star, the fluid rides on a combination of the interior points of the star and the trapped air. The liquid-air interface presents virtually no resistance to flow. The only friction present is that created by the fluid contacting the interior points of the star. The area of the micro Starbore capillary actually in contact with the fluids is only a fraction of the contact area in a similar-sized circular bore capillary.

The liquid column “glides” down the center of the micro Starbore capillary tip, achieving a much greater flow rate at a much smaller pressure drop than that predicted for a circular bore capillary of the same working diameter.

Micro Pipette Electrode: The micro Starbore capillary has been proven to be the best material for micro electrodes since it appeared in 1978. This Radnoti invention evolved from collaboration with Dr. Rodolpho Llinas of the New York University Medical Center.

Catalog# Description O.D. +/- 3% Pieces per vial Store
001811 Micro Star Capillary 1.0mm 50 Add To Cart
001815 Micro Star Capillary 1.5mm 50 Add To Cart
001818 Micro Star Capillary 1.8mm 50 Add To Cart