Ultrasonic fabrication of micro nozzles from a stack of PVDF foils for generating and characterizing microfluidic dispersions

作者：Liao S; Sackmann J; Tollkoetter A; Pasterny M; Kockmann N^*; Schomburg W K^*

来源：Microsystem Technologies, 2017, 23(3): 695-702.

DOI：10.1007/s00542-015-2708-z

Nozzles with circular cross-section and a diameter varying in axial direction have been fabricated in a microfluidic channel from polyvinylidene fluoride as chemically resistive thermoplastic polymer. Smallest diameter and length of the nozzle are approximately 150 A mu m and 3.4 mm, respectively. The nozzle and the entire channel system have been fabricated from two halves generated by ultrasonic hot embossing and bonded to each other by ultrasonic welding. Alignment during ultrasonic welding was assisted by a fit of energy directors and an accuracy of 35 and 10 A mu m in normal and lateral direction, respectively, was obtained. Thermoplastic molding of the two halves of the channel structures was performed by ultrasonic hot embossing with a cycle time of a few seconds. The development was significantly accelerated by milling the tools directly into aluminum plates. This way, new designs were realized within a day. The micro nozzles have been proven generating liquid/liquid dispersions of different flow patterns as a function of flow velocity and Capillary number.

• 出版日期2017-3
• 单位TU Dortmund