Gast ::
| Hauptseite > Publikationsdatenbank > Introduction of New Rotational Mini-Rheometer for Scarce Sample |
| Hauptseite > Publikationsdatenbank > Introduction of New Rotational Mini-Rheometer for Scarce Sample |
| Conference Presentation (Other) | FZJ-2024-07141 |
; ; ;
2024
Abstract: We introduce a miniaturized stress-controlled rheometer, aimed at enhancing rotational rheometry for analysis of scarce sample in material science and product development. This innovative device addresses the critical need for analyzing samples, such as biofilms, nascent drug formulations,and rare metal inks for microelectronics, which are typically limited in quantity due to their high production costs, challenging synthesis, or exclusive origins. Rheological measurements typically require at least 20 μl of sample material using commercial rotation rheometer, a requirement significantly reduced by our device. The mini-rheometer, approximately the size of a 50mm cube, utilizes in particular an air bearing rotor made of quartz glass, manufactured via Selective Laser Etching (SLE). This subtractive 3D printing method for glass ensures the precision needed e.g. for air bearing with μm-scale gaps. An outer magnetic field generated by two orthogonal coil pairs drives a centrally-placed magnet. Torque precision is maintained through applied current and the phase angle between inner and outer magnetic fields. The angular displacement is accurately gauged by two Hall effect sensors, that detect the rotational movement of the inner magnet. The mini-rheometer´s efficiency and functionality were tested performing a simple shear stress experiment on silicon reference oil. Notably, the employed cone-plate geometry only requires 2 μl of sample material, representing a significant advancement in sample conservation. This development extends the benefits of rotational rheometry - such as a wide range of strain rates and homogeneous strain profiles - to experiments where sample availability is limited. Due to the device´s miniaturized dimensions common, inverted microscopes could be used to study microstructural properties related to macroscopic flow behavior.
|
The record appears in these collections: |
