Flexure mechanisms made of metals have been utilized in precision instruments for several hundreds of years, but until recently, you could not procure one made out of fused silica glass. Pity! Because fused silica flexures may be the best option for your precision application, really!
Flexures are compliant elements that connect rigid bodies. The function of a flexure mechanism is to maintain a precise spatial relationship between rigid bodies, while simultaneously providing sufficient compliance to accommodate relative motion in a desired direction. Precision mechanisms often use flexure-based mechanisms for their deterministic behavior and the absence of friction, stiction, and backlash. Flexures allow for displacements that are smooth and continuous.
Larger size flexures are normally made from some metal. In MEMS they are made of silicon. And now at Translume, we fabricate them out of fused silica glass.
Flexures that are made of fused silica have several distinctive characteristics:
- They can go through millions of motion cycles without exhibiting any irreversible deformations. This is not the case with metal flexures – All metals are somewhat plastic and they will progressively exhibit irreversible deformations when repeatedly actuated. For metrological applications, the progressive “creep” associated with metal flexures is a serious issue. A flexure based metrology instrument with metal flexures can progressively and insidiously get out of compliance. On the other hand, with fused silica flexures, you will be able to obtain predictable, repeatable motions (even at atomic resolution) again, and again, and again.
- Fused silica flexures are mainly insensitive to temperature changes. Fused silica has a coefficient of thermal expansion: 5.5×10−7/°C (average from 20 °C to 320 °C) that is almost two orders of magnitude smaller than that of most metals.
- And of course, Fused silica flexures will not rust, tarnish, or otherwise be affected by their environment.
You can learn more about fused silica flexures, their characteristics, and some of their applications by following these links:
- Professor Bellouard, Eindhoven University of Technology, reports on the mechanical properties of fused silica flexures manufactured with our femtoEtch process.
- NIST demonstrates state-of-the-art accelerometer based on Translume’s fused silica flexures
- Translume demonstrates cantilevers with integrated optical waveguide
- Flexure-based linear translation stage with integrated optical position sensor
- Optics-Based Force and Position Micro-Sensors with Fused Silica Flexures
- Flexure with integrated Mach-Zehnder interferometer
- Springs made out of fused silica