3D printed measuring device for the determination the surface tension of nanofluids

The paper presents a method for building a low-cost tensiometer to measure the interfacial surface tension between liquid and air. The project is based on common and well-known devices (analytical balance, Arduino micro controller, DC motor) and manufacturing techniques (CAD, 3D printing), mostly available in scientific and industrial laboratories. For the control of proposed devices the user-friendly software with graphical user interface was prepared in an open-source widget toolkit Qt with the use of programming language C++. The source code of the software and CAD models for printing components that allow to the self-build of the described tensiometer, were provided. Finally, the proposed measuring device was used to determine the surface tension of two types of ethylene glycol based nanofluids containing silicon nitrides and multi-walled carbon nanotubes. It was presented that proposed device could be successfully used with complex systems like nanofluids, even in case that commercially available equipment fails.