| 摘要 |
<p>22 Perfectly spherical, smooth and uniform microcapsules, which may contain living cells, are produced having a diameter less than 700 .mu.m by employing an electrostatic droplet generator. A droplet is suspended from a pointed source, such as a needle, and is charged with high static voltage. A collecting vessel or ring device is charged with opposing polarity and attracts the droplet. When a voltage potential threshold is passed, the droplet moves from the source to the collecting vessel. The voltage pulse height, pulse frequency and length, and extrusion rate of the droplet are adjustable so that predetermined sizes of droplets may be repeatedly generated and collected.</p> |
