Liquid metal actuators: Correctable mounting and assembly of thin-shell x-ray telescope mirrors

Alexander R. Bruccoleri, Martin Klingensmith, Brandon Chalifoux, Ralf K. Heilmann, Mark L. Schattenburg

Research output: Chapter in Book/Report/Conference proceedingConference contribution

2 Scopus citations


An ideal bonding agent for thin-shell x-ray mirrors could be quickly applied to joints and set with deterministic and stable properties. Unfortunately, mirror assembly methods have typically utilized various epoxy formulations which are messy, slow to apply and cure, and far from deterministic or stable. Problems include shrinkage, creep and high thermal and humidity sensitivity. Once the bond is set errors are frozen in and cannot be corrected. We are developing a new method for bonding thin-foil mirrors that has the potential to solve these problems. Our process to bond mirrors to housing reference points is achieved via small beads of a low-melting-point bonding agent (such as solder or thermoset). The mirror is bonded to small contact surface points under real-time metrology. If the position of the mirror needs to be adjusted after bonding, a small force is applied normal or parallel to the contact surface and a pulsed fiber laser is used to melt an ultrathin layer of the solder for a very short time. The joint is then compressed, stretched or sheared while molten before refreezing in a new position, enabling repeatable and stable mirror position adjustments along the direction of the force in nm-level steps with minimal heat input. We present results from our prototype apparatus demonstrating proof of principle. The initial experiment includes developing a technique to bond D263 glass to Kovar, designing and building a one-dimensional stage to precisely apply force, and using an infrared laser pulse to heat the joint while measuring position and force.

Original languageEnglish (US)
Title of host publicationOptics for EUV, X-Ray, and Gamma-Ray Astronomy VII
EditorsGiovanni Pareschi, Stephen L. O'Dell, Giovanni Pareschi, Stephen L. O'Dell
ISBN (Electronic)9781628417692, 9781628417692
StatePublished - 2015
Externally publishedYes
EventOptics for EUV, X-Ray, and Gamma-Ray Astronomy VII - San Diego, United States
Duration: Aug 10 2015Aug 13 2015

Publication series

NameProceedings of SPIE - The International Society for Optical Engineering
ISSN (Print)0277-786X
ISSN (Electronic)1996-756X


ConferenceOptics for EUV, X-Ray, and Gamma-Ray Astronomy VII
Country/TerritoryUnited States
CitySan Diego


  • Adjustable Bonding
  • Laser Heating
  • Liquid Metal
  • Precision Engineering
  • Solder
  • X-ray Optics

ASJC Scopus subject areas

  • Electronic, Optical and Magnetic Materials
  • Condensed Matter Physics
  • Computer Science Applications
  • Applied Mathematics
  • Electrical and Electronic Engineering


Dive into the research topics of 'Liquid metal actuators: Correctable mounting and assembly of thin-shell x-ray telescope mirrors'. Together they form a unique fingerprint.

Cite this