Biomedical Microdevices

, Volume 10, Issue 1, pp 123–128 | Cite as

Evaluating the process of polishing borosilicate glass capillaries used for fabrication of in-vitro fertilization (iVF) micro-pipettes

Article

Abstract

In this paper we investigate a number of gas flames for fire polishing borosilicate glass capillaries used in the manufacturing of IVF micro-pipettes. Hydrofluoric acid (HF) was also used as an alternative to finish the pipette end. Glass micro tools in the IVF industry are drawn from hollow glass capillaries of diameter 1 mm. These capillaries are cut manually to a length of 100 mm from hollow glass rods resulting in sharp and chipped edges. These capillaries are held in a customised holder having padding of soft silicone or rubber. Sharp and uneven edges of these capillaries pick up particles of rubber or soft silicone shavings, rendering them ineffective for IVF treatments. The working range of borosilicate glass is 800–1,200°C. The experiments involved analysis of fire polishing process for borosilicate glass capillaries using candle, butane, propane, 2350 butane propane, oxyacetylene gas flames, finding the optimum distance of the capillary relative to the flame, optimum time for which the capillary should be held in the flame and optimum region of the flame which gives the required temperature range. The results show that 2350 butane propane gas mix is optimum for fire polishing of borosilicate glass capillaries. The paper is concluded by comparing the results of fire polishing with the results of acid polishing, in which HF of 1.6% concentration is used to etch the ends of the borosilicate glass pipettes.

Keywords

Firepolishing Micro-pipettes In-vitro fertilization Borosilicate glass 

Reference

  1. I. Avramov, T. Vassilev, The glass transition temperature of silicate and borate glasses. J. Non-Cryst. Solids 351, 472–476 (2004)CrossRefGoogle Scholar
  2. V Babrauskas, Temperatures in Flames and Fires (Fire Science and Technology, Issaquah, WA, 1998)Google Scholar
  3. M. Goodman, S Lockery, Pressure polishing: a method for re-shaping patch pipettes during fire polishing. J. Neurosci. Methods 100, 13–15 (2000)CrossRefGoogle Scholar
  4. M. Harz, H Engleke, Curvature Changing or flattening of anodically bonded silicone and borosilicate glass. Sens. Actuators 55, 201–209, (1996)CrossRefGoogle Scholar
  5. W. Kingery, H. Bowen, D. Uhlmann, Glasses, Introduction to Ceramics, 2nd edn. (John Wiley and Sons, New York, 1976), pp. 7.1–7.20Google Scholar
  6. R. Lehman, The Mechanical Properties of Glass, Theoretical Strength, Practical Strength, Fatigue, Flaws, Toughness, Chemical Processes, Glass Engineering 150:312, (Department of Ceramics and Material Engineering, Rutgers University New Jersey USA, 1998), pp. 1–15Google Scholar
  7. Schott, Types of technical glasses, physical and technical properties (Schott Technical Glasses, Germany, 2000), pp. 1–40Google Scholar
  8. O. Sylvania, Thermal performance of borosilicate tubing. Tech. Inf. Bull. 1–8, (2004)Google Scholar
  9. V. Venkatesh, S. Mahadevan, electro-chemical mechanical polishing of copper and chemical mechanical polishing of glass, J. Mater. Process. Technol. 149, 493–498, (2004)CrossRefGoogle Scholar
  10. W. Xiaosheng, C. Wenyuan, W. Lijiang, L. Xiangyang, Z. Weiping, C. Xiaomei, Non-abrasive polishing of glass, Int. J. Mach. Tools Manuf. 42, 449–456, (2002)CrossRefGoogle Scholar

Copyright information

© Springer Science+Business Media, LLC 2007

Authors and Affiliations

  1. 1.Medway School of EngineeringUniversity of GreenwichKentUK
  2. 2.Hunter Scientific Ltd.EssexUK

Personalised recommendations