ULTRA-LIGHT, SELF-CORRECTING, “LIVE” MIRRORS: Lowering the areal density of mirrors and maximizing performance with non-abrasive, additive, 3D-printed novel technology.

Introduction

We propose to develop ultralight, self-correcting mirrors for use in the next generation of large optical telescopes and solar energy concentrators. Presently, the best mirrors have a density of about one-half a metric ton per square meter or more in order to provide the stiffness which is necessary to keep the optical shape under the variable conditions given by the changing gravity vector as the telescopes track a position on the sky, as well as to withstand variable wind conditions.

Proposed Solution

We intend to replace such a massive mirror with a “sandwich” of very light, optically perfect, “fire-glass” (window pane) coated sheets stiffened with layers of Electro-active polymers that can be deposited through additive manufacturing 3D printers.

Manufacturing Process

1. The sheets of glass will be heated to ~800°C in a pressurized, tailored-made kiln.
2. They will be allowed to relax (their backside) onto a suitable mold, cast to a predetermined off-axis aspheric (parabolic) shape.
3. The temperature will be kept below the de-vitrification temperature of the glass, thus preserving the excellent optical surface quality of fire-glass window pane.

Dynamic Control

Using the addressable energy of the Electro-active polymers will provide not only dynamically self-controlled stiffness but also variable push-pull action real-time multi-sensing controlled and calibrated in order to keep the optical surface to a “live-perfect” shape under general operating conditions.

Benefits

These “Live-Mirrors” shall provide optical surfaces of as high a quality as those of the current best telescopes but with:

• Larger dynamic range
• A reduction in weight and cost of more than one order of magnitude

Such mirrors will allow the development of 50-100 meter-class telescopes as well as of the next generation of space telescopes.

Applications

On the ground, they will also offer very low-cost options for:

• The next generation of solar energy concentrators
• Antennas used for optical communications