Modular Microscope Accessory (MMA)
The Modular Microscope Accessory (MMA) enables complete flow visualization – including counter-rotation – with simultaneous rheological measurements on a Discovery Hybrid Rheometer. A high-resolution camera collects images at up to 90 fps coupled with industry-standard microscope objectives that provide magnification up to 100×. Illumination from a blue-light LED can be coupled with a cross-polarizer or dichroic splitter for selective illumination or fluorescence microscopy.
The MMA mounts directly to the Discovery Hybrid Rheometer and does not require any additional stands, lifts, or other support. This makes the system simple to install and effectively isolates it from external vibration and other sources of environmental interference that would compromise image quality. A precision x-y-z micrometer positioning system allows the microscope’s field of view to be placed anywhere within the sample. This allows for investigation of flow homogeneity anywhere from the axis of rotation to the sample edge. Precise depth-profiling is enabled by an optional Piezo-scanning system. This precision mechanism permits the depth of the focal plane to be adjusted in software-controlled increments over a 100 µm range for quantitative depth-profiling with steps as small as 0.1 mm. The MMA is compatible with the Upper Heated Plate (UHP) for temperature control from -20 °C to 100 °C.
Counter-rotation: Stagnation Plane Microscopy
When visualizing materials under flow at high shear rates, features of interest can rapidly move across the field of view, imposing limits on the time available to observe shearinduced changes in the sample. An optional counter-rotation stage available for the MMA rotates the lower glass plate at a constant velocity in a direction opposite to that of the upper plate – this creates a zero-velocity stagnation plane where the fluid is stationary with respect to the camera, allowing a fixed field of view throughout the experiment. The location of this zero-velocity plane within the gap can be controlled by varying the ratio of the upper and lower plate velocities without changing the effective shear rate across the sample. This counter-rotation system is a Smart Swap accessory that can be added at any time.
Features and Benefits
- Smart Swap technology for quick installation
- Available counter-rotation for stagnation plane imaging on any Discovery Hybrid Rheometer
- High resolution, high frame-rate image collection
- Effective temperature control through Upper Heated Plate (UHP)
- Direct sample temperature measurement with Active Temperature Control
- Visual access to any position within the measurement area, e.g. center, edge, or mid-radius
- Optional cross-polarization, fluorescence, and precision depth-profiling
- Wide selection of commercially-available objectives