Adaptive zoom: Prototype riflescope has push-button magnification

A member of the US Army Special Forces, left, demonstrates the Rapid Adaptive Zoom for Assault Rifles prototype developed at Sandia National Laboratories.

by Heather Clack

When an Army Special Forces officer-turned engineer puts his mind to designing a military riflescope, he doesn’t forget the importance of creating something for the soldiers who will carry it that is easy to use, extremely accurate, light-weight, and has long-lasting battery power.

Sandia optical engineer Brett Bagwell (5331) led the development of the Rapid Adaptive Zoom for Assault Rifles (RAZAR) prototype. At the push of a button, RAZAR can toggle between high and low magnifications, enabling soldiers to zoom in without having to remove their eyes from their targets or their hands from their rifles.

“The impetus behind the idea of push-button zoom is you can acquire what you’re interested in at low magnification and, without getting lost, zoom in for more clarity,” Brett says.

In addition to military riflescopes, RAZAR technologies are now being considered for other applications where speed, size, weight, and power count. Applications include medical imaging, binoculars for the entire range of users from the military to birdwatchers, hunters’ scopes, and cell phone cameras where optical zoom is needed to avoid the pixelated images associated with digital zoom.

Adaptive zoom is Sandia’s answer to DoD call for riflescope

Brett began work on RAZAR in 2006 responding to DoD interest in a compact zoom riflescope that could rapidly toggle between magnifications. Early work had been funded by Sandia’s Laboratory Directed Research and Development program.

Brett found no commercial products or components that would enable the riflescope to meet military requirements, so his team had to design and build the first RAZAR from scratch and develop a manufacturing process.

The RAZAR prototype uses a patented active optical zoom system called “adaptive zoom,” which was invented by David Wick (1932), who was working as an optical engineer at the time.

Traditional optical zoom changes magnification by adjusting the positions of the lenses along the optical axis. For example, a 35-mm camera mechanically moves the lenses as you zoom in on or out from a subject.

Adaptive zoom changes the focal lengths of two or more lenses by varying the curvature of the lenses’ surfaces to provide optical zoom without changing their overall positions relative to one another, allowing the user to view either a wide-angle image or zoom in on an area of interest with a compact, low-power system, David says.

The invention, Brett says, means “this is the first time in a long time that there has been a new technology that a direct-view optical designer can take advantage of.”

Three core technologies make adaptive zoom work for RAZAR:

  • A polymer lens core has two flexible, hermetically sealed membranes, which encapsulate a polymer fluid. The three-quarter-inch lenses are aligned with glass lenses to complete the optical design.
  •  A piezoelectric actuator electromechanically changes the flex of the lenses, achieving the correct position within 250 milliseconds to an accuracy of 100 nanometers, about 1/100th the thickness of a human hair. These actuators operate similar to the way the muscles of the human eye change the curvature of the eye‘s lens to focus far away or up close.
  • Variable-focal length system design tools had to be developed from scratch, including analytical expressions and computer models that trace rays of light through optical systems.

Riflescope’s peak optical quality half a light wave

Variable optical lenses were first developed in the late 1800s but had few applications because of the limitations of materials. Adaptive zoom accomplishes true optical zoom (as opposed to digital zoom) by changing the focal length of two or more lenses in concert, without the normal mechanical motion, reducing the size and power requirements of the zoom lens, David says

The theory that underlies zoom scopes hadn’t changed significantly since the 1960s, until the adaptive zoom technology came along. Using adaptive zoom, Sandia’s team worked for 18 months to achieve an optical quality of about half a wavelength of light.

Manufacturing process developed to guarantee lens quality

Sandia had to perfect the manufacturing process of the lenses so the quality of the prototype could be replicated. When the polymer is sealed, no air bubbles or specks of dust could remain in the lenses or on the surrounding rings, Brett says.

Freddie Santiago (5331), a doctoral candidate in physics at the University of New Mexico who is part of Sandia’s Student Internship Program, developed the process for making the lenses.

“You have to start from the basics: How do we make the polymer? How do we stretch the polymer and make it an optical surface? We had to understand the process, from mixing the polymer all the way to the final product and we had to do it in a systematic way,” Freddie says. This systematic approach was aided by his Lean Six-Sigma training, for which he earned a Black Belt.

Small business tapped to design actuator

While many of the technologies and designs that make up the riflescope came from mechanical engineers, robotics experts, chemists, and other Sandia experts, Brett went outside the Labs for the actuator to flex the lenses, seeking help from Dynamic Structures and Materials, LLC, a small business in Franklin, Tenn.

Matthew Stefanick, the company’s lead engineer on the project, says the team used an ultrasonic piezo motor to actuate the flex in the lenses. A voltage is applied at an ultrasonic frequency to vibrate and move a rotor and lead screw, which causes the lens to flex.

Stefanick says the decision to use an ultrasonic motor provided a key feature, a “zero-power hold,” which maintains the last selected focus, even if power is lost.

The feature allows users to complete 10,000 actuations on two AA batteries, Brett says.

Meeting the power usage, speed, and accuracy specifications required by the military took years. “As an engineer, I was impressed with our progress,” Brett says. “But as an operator, I was constantly dissatisfied. We had to make it smaller. We had to make it lighter. It’s got to toggle faster.”

Ex-sergeant says riflescope could save lives

From 2010-2012, the team also ensured the riflescope would be reliable in the field by conducting shock, vibration, and temperature testing, Brett says.

By 2010, Brett began demonstrating it to the military and, in late 2012, tested it with representatives from US Special Operations Command at Camp Atterbury Joint Maneuver Training Center near Edinburgh, Ind. When he handed the rifles to military personnel to test them, he realized that Sandia had developed a concept that would benefit the military.

“The guys picked it up and when they pushed the button and it zoomed, and then instantly zoomed back out, they were like kids at Christmas. There was this look of astonishment and pleasure,” he says. “That’s very gratifying. Here’s this grizzled veteran looking at me like I’ve just created magic.”

Michael Squire, then-sergeant first class with Special Operations Research Support Element, says the ability to zoom between near and far targets within seconds without taking his hand off the weapon is “game-changing.”

“The difference that can make, especially with somebody shooting back, could mean life or death,” he says.

Feedback from ex-military personnel and soldiers who have tried RAZAR has motivated Brett. He is now working to develop night vision systems and recently demonstrated adaptive zoom in thermal infrared.

“It’s an opportunity for me to take my technical expertise and give back to people I really care about,” he says.

-- Heather Clack

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‘Tinkertoy’ materials with colorful solar cells for increased photovoltaic efficiency

SCHEMATIC of light-harvesting mechanisms available in MOFs - (M: metal ions; L1,L2: linkers; yellow sphere: guest molecule) The modular, multifunctional structure provides three possible light harvesting mechanisms in MOFs: A) one or more organic linker types within a framework; B) light-absorbing guest molecules in the pores; and C) charge transfer interactions between guest molecules and MOF linkers that produce new absorption to the red of the isolated guest and linker.

by Mike Janes

Sandia researchers have received a $1.2 million award from DOE’s SunShot Initiative to develop a technique that they believe will significantly improve the efficiencies of photovoltaic materials and help make solar electricity cost-competitive with other sources of energy.

The work builds on Sandia’s recent successes with metal-organic framework (MOF) materials by combining them with dye-sensitized solar cells (DSSC).

 “A lot of people are working with DSSCs, but we think our expertise with MOFs gives us a tool that others don’t have,” says Sandia’s Erik Spoerke (1816), a materials scientist with a long history of solar cell exploration at the Labs.

Sandia’s project is funded through SunShot’s Next Generation Photovoltaic Technologies III program, which funds projects that apply promising basic materials science that has been proven at the materials properties level to demonstrate photovoltaic conversion improvements to address or exceed SunShot goals.

The SunShot Initiative is a collaborative national effort that aggressively drives innovation to make solar energy fully cost-competitive with traditional energy sources before the end of the decade. Through SunShot, the Energy Department supports efforts by private companies, universities, and national laboratories to drive down the cost of solar electricity to $0.06 per kilowatt-hour.

A basis for future advancements

Dye-sensitized solar cells, invented in the 1980s, use dyes designed to efficiently absorb light in the solar spectrum. The dye is mated with a semiconductor, typically titanium dioxide, that facilitates conversion of the energy in the optically excited dye into usable electrical current. 

DSSCs are considered a significant advancement in photovoltaic technology since they separate the various processes of generating current from a solar cell. Michael Grätzel, a professor at the École Polytechnique Fédérale de Lausanne in Switzerland, was awarded the 2010 Millennium Technology Prize for inventing the first high-efficiency DSSC.

 “If you don’t have everything in the DSSC dependent on everything else, it’s a lot easier to optimize your photovoltaic device in the most flexible and effective way,” says Sandia senior scientist Mark Allendorf (8300). DSSCs, for example, can capture more of the sun’s energy than silicon-based solar cells by using varied or multiple dyes, and also can use different molecular systems, Mark says.

 “It becomes almost modular in terms of the cell’s components, all of which contribute to making electricity out of sunlight more efficiently,” says Erik.

MOFs to the rescue

Though a source of optimism for the solar research community, DSSCs possess certain challenges that the Sandia research team thinks can be overcome by combining them with MOFs.

Mark says researchers hope to use the ordered structure and versatile chemistry of MOFs to help the dyes in DSSCs absorb more solar light, which he says is a fundamental limit on their efficiency.

 “Our hypothesis is that we can put a thin layer of MOF on top of the titanium dioxide, thus enabling us to order the dye in exactly the way we want it,” Mark explains. That, he says, should avoid the efficiency-decreasing problem of dye aggregation, since the dye would then be locked into the MOF’s crystalline structure.

MOFs are highly ordered materials that also offer high levels of porosity, says Mark, an MOF expert and 29-year veteran of Sandia. He calls the materials “Tinkertoys for chemists” because of the ease with which new structures can be envisioned and assembled.

Mark says the unique porosity of MOFs will allow researchers to add a second dye — placed into the pores of the MOF — that will cover additional parts of the solar spectrum that weren’t covered with the initial dye. He and Erik are convinced that MOFs can help improve the overall electron charge and flow of the solar cell, which currently faces instability issues.

 “Essentially, we believe MOFs can help to more effectively organize the electronic and nanostructure of the molecules in the solar cell,” Erik says. “This can go a long way toward improving the efficiency and stability of these assembled devices.”

In addition to the Sandia team, the project includes researchers at the University of Colorado-Boulder, particularly Steve George, an expert in a thin film technology known as atomic layer deposition. The technique, Erik says, is important in that it offers a pathway for highly controlled materials chemistry with potentially low-cost manufacturing of the DSSC/MOF process. “With the combination of MOFs, dye-sensitized solar cells, and atomic layer deposition, we think we can figure out how to control all of the key cell interfaces and material elements in a way that’s never been done before,” says Erik. “That’s what makes this project exciting.”



-- Mike Janes

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‘Small business is HUGE’ . . . When companies call Sandia, they get a person

Ann Riley’s (10222) is the first voice many business people hear when they reach out to Sandia as potential suppliers. “If they say Ms. Riley, I say, ‘Call me Ann.’ We become friends,” Ann says. “They are absolutely blown away that Sandia provides such a service. They can’t believe a company this size has a real person to talk to.” (Photo by Randy Montoya)

by Nancy Salem

Danny Ruiz was surprised when he called Sandia for business information and heard a live voice. “You don’t normally get that with federal agencies,” he says. “It was awesome to have someone to talk to and figure out how to work together and do business with Sandia.”

The person who picked up the phone was Ann Riley (10222), a member of the Small Business Utilization team and Sandia’s Business Point of Contact (BPOC). The BPOC fields all calls from people who want to become Sandia suppliers. “It’s about providing great customer service,” Ann says. “Most of the callers are small companies, and we’re here to help them.”

Ruiz, of Mazda Computing in the Sandia Science and Technology Park, ultimately won a Sandia contract. He credits in part the personal service he received. “It works very well,” he says. “And it doesn’t end with the contract. Ann still calls every now and then to see how we’re doing. The process is great.”

The BPOC was launched five years ago to help people who wanted to do business with the Labs but didn’t know how. “People would try to find somebody, anybody, they could talk to,” Ann says. “We didn’t want to create a system where an automated voice said, ‘Press one, press two, press three.’ Everyone knows how frustrating that is.”

The BPOC is designed to connect businesses to a person who can answer questions and solve problems in a single phone call. “Before the BPOC people became very frustrated,” says Don Devoti, manager of Small Business Utilization Dept. 10222. People complained about how difficult it was to do business with Sandia. “Now callers get to the right person every time.”

The BPOC phone number (800-765-1678) and email address ( are on Sandia’s external website. In addition to the dialog with the BPOC, each person who calls receives a letter with detailed instructions on what to do next as an interested supplier. Ann also walks them through the Business Opportunities website, which lists Sandia contracting opportunities.

If the caller is associated with a small business with serious potential to be a Sandia supplier, he or she is referred to a Sandia small business advocate, who follows up. “Small business is huge at Sandia,” says Ann, a former small-business owner. The Labs spend about $500 million a year with small companies, more than half of them in New Mexico.

An honest assessment

Krista Smith, senior manager of Policy, Assurance, and Outreach Dept. 10220, says, “Our goal is to give suppliers an honest assessment of whether or not their products or services match Sandia’s needs. We also want to let them know the rigor involved in working with Sandia, like our stringent safety and quality requirements. We know that it is expensive for suppliers to pursue new business, so we aim to make their first inquiry as informative and efficient as possible.”

If there does not appear to be an opportunity for a supplier at Sandia, the BPOC may refer the company to contracting agencies such as Kirtland Air Force Base, local governments, or other federal labs.

In fiscal year 2014 Sandia’s BPOC responded to 2,161 calls and 3,892 emails from all over the world. Ann sets the tone by making the caller feel comfortable. “If they say Ms. Riley, I say, ‘Call me Ann.’ We become friends,” she says. “They are absolutely blown away that Sandia provides such a service. They can’t believe a company this size has a real person to talk to. I get that over and over again.

“This is about helping our supplier community, especially our small businesses, figure out this huge entity called Sandia National Laboratories and alleviating the fear. We want them to start out on the right foot because we know that with nearly half of our annual dollars spent in procurements, we could not be successful without our suppliers.”

Ann says it’s important that internal Sandia organizations also refer calls from outside businesses to Supply Chain and the BPOC. “We don’t want companies to start shopping for business within Sandia using an ad-hoc approach,” she says. “They will get frustrated and we don’t want to give the impression that’s how the system works. We strive to offer a consistent message and avenue to our prospective suppliers.”

Theresa Carson, manager of Information Systems and Science, Technology, and Research Procurement Dept. 10244, says the BPOC is an important service to Sandia suppliers. “Having the opportunity to speak to someone who can answer questions about how to do business with Sandia and provide guidance is a valuable benefit,” she says.

Feedback indicates that having the BPOC role enhances Sandia’s image in the business community. “It adds to our credibility, and is another piece of the puzzle to achieving mission success,” Ann says. “And that’s what it’s all about.”


-- Nancy Salem

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