Lab on a chip
Micro channels are fabricated in a few seconds from polymer foils by ultrasonic hot embossing. A new design is realized within one day. Micro channels fabricated this way are joined by ultrasonic welding to standard base plates produced by injection molding. This way, in a short time new microfluidic systems are tested. Applications are found in medicine, biology, and chemistry.
Besides this, it is also possible to emboss a micro channel into a polymer plate by ultrasonic hot embossing and to seal this channel by ultrasonic welding. This way, a polymer chip from poly carbonate (PC) has been fabricated for the development of a test which shall be employed to measure the calcification risk of patients (cf. the figure) [92]. In this chip, there are micro structures preventing air bubbles entering through the inlets into the mixing channel. On the bottom of the mixing channel there are riffles facilitating mixing of fluids and at the end of the channel there is a cuvette in which a bio-chemical reaction indicating the calcification risk can be optically observed.
In a titer plate with 48 wells, there were ultrasonically welded three opto-chemical sensors onto the bottom of each well [75]. This way, it is possible measuring the concentration of oxygen, carbon dioxide and pH value of the fluids in all the wells simultaneously with a single camera. To achieve this, the sensors are excited to fluorescence through the bottom of the titer plate and the emitted light is measured with the camera and analyzed.
References:
[92] P. Maurer, S. Gräber, W. Jahnen-Dechent, W.K. Schomburg, "Polymer Micro Chips for the Analysis of Calcification Risk", Procedia Engineering 168 (2016) 1386 - 1389, doi: 10.1016/j.proeng.2016.11.386.
[75] S.Krabbe, D.E. Achatz, C.Gerhardy, W.K. Schomburg, "Ultrasonic welding of chemical optical sensors supporting O2, pH and CO2 imaging in microfluidic systems", Procedia Engineering 120 (2015) 598 - 601, doi: 10.1016/j.proeng.2015.08.736.