What is acoustobond
Acoustobond is refined yacca gum, derived from the Australian grass tree Xanthorroea Preissii. It has been used for millennia to attach stone spear tips. It can be used to join metal and glass with minimal acoustic losses. The resin is hard and brittle at room temperature and below, but is soft at 80ºC and quite liquid above 100ºC. It has a glassy dark brown appearance.
This unique resin is found on the trunks of Xanthorroea Preissii plants after severe bush fire. It is collected without damage to the trees and carefully refined to create this product.
The glue is soluble in ethanol but insoluble in water. Joints can be undone by heating and surfaces can be cleaned in ethanol. Acoustobond resin has been used in low acoustic loss, low optical loss experiments involving moderate laser power and high vacuum. We have no evidence of vacuum incompatibilities, nor contamination of optical surfaces.
For minimum acoustic loss, joints should be very thin. Small resin chips should be placed between the surfaces desired for bonding. Mild radiant heat (eg a halogen light) can be used to soften the resin. The light should heat the resin to 100ºC. Other methods of heating include the use of an oven, or a CO2 laser. Pressure allows resin to spread across the bonding surface.
Acoustobond has been used successfully to:
- attach fused silica mirrors to high Q-factor niobium resonators (f ~ 5kHz, Q ~ 10^6)
- minimise suspension losses in MHz silicon resonators and silicon nitride membranes
- repair a broken silicon cantilever