Georgia Tech Investigates Liquid Crystal Polymer for NASA Applications

Aug 22, 2006
Georgia Tech Investigates Liquid Crystal Polymer for NASA Applications
This close-up shows an antenna array embedded on liquid crystal polymer (right). To the left is a large sheet of the flexible, weather-resistant polymer. Georgia Tech Photo: Gary Meek

Researchers at the Georgia Institute of Technology have received funding from the NASA/Earth Science Technology Office to evaluate a material called liquid crystal polymer (LCP) for electronics applications in space.

The ultra-thin, paper-like plastic can incorporate a variety of electronic circuits, yet it molds to any shape and appears to perform well in the extreme temperatures and intense radiation encountered by NASA spacecraft.

George E. Ponchak, a co-investigator and senior research engineer at NASA’s Glenn Research Center in Cleveland, Ohio, said research to date indicates that LCP outperforms conventional materials for antennas and circuit boards in high-frequency radio applications aboard space vehicles.

“I think the chances are very high that LCP will be practical for a variety of NASA applications,” Ponchak said.

Light weight is the material’s biggest potential benefit to NASA, he said. Flexible LCP antennas would be lighter than today’s structured antennas, and LCP-based circuits molded to available spacecraft areas could eliminate heavy metal boxes that currently house rigid circuit boards.

“Less weight lets us move to a smaller launch system, which in turn saves a lot of money,“ Ponchak said.

John Papapolymerou, a professor in the Georgia Tech School of Electrical and Computer Engineering, explains that LCP’s unique structure – aromatic crystal polyester comprised of benzene rings, acetyloxy polymers, and carboxyl groups – allows it to be heat resistant, flexible and strong while also possessing excellent electrical performance.

Moreover, the material can serve as a highly efficient substrate – material on which semiconductor chips are attached – as well as the backplane that connects those chips together, said Papapolymerou, who with Prof. Manos Tentzeris leads a team researching LCP. Even micro-electromechanical system (MEMS) devices could be embedded on LCP, along with integrated circuits.

“It's like having a PC board type of technology that has many other advantages,” Papapolymerou said. “We are already developing LCP-based technology for NASA applications, and I think eventually you will see LCP in next-generation consumer systems.”

Among the material’s advantages:

-- It is “near-hermetic” – highly resistant to humidity and other environmental conditions. It could be applied almost like wallpaper to space and other vehicles, forming large antennas aloft.

-- It effectively processes radio frequencies (RF) up to 110 GHz, which is well into the millimeter wave range used for radars as well as for military and scientific communications. By contrast, conventional circuit-board RF capabilities dwindle swiftly above 5 GHz.

-- It is cheaper to make than competing hermetic technologies such as ceramic substrates.

-- Its thermal-expansion properties allow it to form multi-layer structures that won’t crack or delaminate. That could lead to three-dimensional circuits that provide both reliability and a smaller footprint.

Papapolymerou and Tentzeris have received two three-year awards from the NASA/Earth Science Technology Office to pursue LCP-related applications. They are currently developing a precipitation-radar application that NASA could use to monitor global water cycling. In addition to NASA, the National Science Foundation is also supporting Georgia Tech’s LCP work.

Recent LCP-related publications by the Georgia Tech LCP team have appeared in IEEE Microwave and Wireless Components Letters, IEEE Antennas and Wireless Propagation Letters, and IEEE Transactions on Advanced Packaging.

NASA’s Ponchak notes that LCP still has hurdles to clear before it can be used in space. Though the material has performed well at high temperatures, it must still complete low-temperature and radiation tests. If it passes those tests, it could be incorporated into NASA spacecraft designs within two years, he said.

Papapolymerou believes that RF circuits for communications and radar are LCP’s most promising application thus far. But Georgia Tech engineers are also investigating the robust polymer’s capacity to embed analog and digital chips, RF MEMS devices and RF circuits together in one flexible, weather-resistant package.

Currently, Papapolymerou said, his team is weighing the reliability of RF MEMS switches embedded in LCP. Since RF MEMS devices have moving parts, they are more sensitive to environmental conditions than solid-state devices like chips and RF arrays.

LCP, which has been commercially available for many years, wasn’t always a good candidate for environmentally demanding applications, Papapolymerou said. Ten years ago the malleable material tore easily, but changes in LCP chemistry have dramatically improved its strength and reliability.

The low cost of conventional circuit boards will probably bar the material from most applications below 5 GHz, he believes. But above that threshold LCP could have numerous uses, including wireless LAN at 60 GHz and military applications at 30, 40 and 94 GHz . Promising NASA applications include remote sensing precipitation radars at 14 and 35 GHz.

Tentzeris believes that LCP and other similar flexible organics could also be used for a new generation of ultra-wideband sensor and secure communication applications. The flexible nature of LCP, he said, allows easy integration with complex surfaces such as airplanes, cars and trucks. In addition, its light weight and thermal expansion properties could make possible low-cost portable multifunction modules operating in different frequency bands and standards.

He stresses that a major advantage of LCP-type organics lies in the fact that their electrical properties feature only a slight change for frequencies ranging from the low-end of the cellular communications (900-1800 MHz) to the high-end short-range broadband telecom, sensor and radar bands (110 GHz).

Currently, Tentzeris said, his team is developing ultra-broadband / multiband antennas and embedded functions on LCP that could be used for reconfigurable frequency and data-rate telecom and sensor applications. His team is also investigating novel 3D meta-material ideas utilizing LCP to develop flexible lenses and dramatically improve the power efficiency of RF/sensor modules.

Costs must come down before commercial LCP applications can take off, Papapolymerou said. But as production and demand for LCP-based circuits increase, commercial use could become more likely. In fact, he said, LCP-based circuits may play a role in next-generation consumer applications such as sophisticated communications products.

“Devices that must provide a lot of bandwidth – that’s where you will need a substrate that has good, low-cost, small-footprint performance at frequencies like 30 or 60 GHz,” Papapolymerou said. “Conventional circuit-board material will not do the job anymore.”

Source: Georgia Institute of Technology

Explore further: Lifting the brakes on fuel efficiency

add to favorites email to friend print save as pdf

Related Stories

Sun emits a mid-level solar flare

12 minutes ago

The sun emitted a mid-level solar flare, peaking at 9:03 a.m. EDT on April 18, 2014, and NASA's Solar Dynamics Observatory captured images of the event. Solar flares are powerful bursts of radiation. Harmful ...

Magnitude-7.2 earthquake shakes Mexican capital

1 hour ago

A powerful magnitude-7.2 earthquake shook central and southern Mexico on Friday, sending panicked people into the streets. Some walls cracked and fell, but there were no reports of major damage or casualties.

LinkedIn membership hits 300 million

1 hour ago

The career-focused social network LinkedIn announced Friday it has 300 million members, with more than half the total outside the United States.

Plants with dormant seeds give rise to more species

1 hour ago

Seeds that sprout as soon as they're planted may be good news for a garden. But wild plants need to be more careful. In the wild, a plant whose seeds sprouted at the first warm spell or rainy day would risk disaster. More ...

Recommended for you

Lifting the brakes on fuel efficiency

Apr 18, 2014

The work of a research leader at Michigan Technological University is attracting attention from Michigan's Governor as well as automotive companies around the world. Xiaodi "Scott" Huang of Michigan Tech's ...

Large streams of data warn cars, banks and oil drillers

Apr 16, 2014

Better warning systems that alert motorists to a collision, make banks aware of the risk of losses on bad customers, and tell oil companies about potential problems with new drilling. This is the aim of AMIDST, the EU project ...

User comments : 0

More news stories

Ex-Apple chief plans mobile phone for India

Former Apple chief executive John Sculley, whose marketing skills helped bring the personal computer to desktops worldwide, says he plans to launch a mobile phone in India to exploit its still largely untapped ...

Airbnb rental site raises $450 mn

Online lodging listings website Airbnb inked a $450 million funding deal with investors led by TPG, a source close to the matter said Friday.

Health care site flagged in Heartbleed review

People with accounts on the enrollment website for President Barack Obama's signature health care law are being told to change their passwords following an administration-wide review of the government's vulnerability to the ...

A homemade solar lamp for developing countries

(Phys.org) —The solar lamp developed by the start-up LEDsafari is a more effective, safer, and less expensive form of illumination than the traditional oil lamp currently used by more than one billion people ...

NASA's space station Robonaut finally getting legs

Robonaut, the first out-of-this-world humanoid, is finally getting its space legs. For three years, Robonaut has had to manage from the waist up. This new pair of legs means the experimental robot—now stuck ...

Filipino tests negative for Middle East virus

A Filipino nurse who tested positive for the Middle East virus has been found free of infection in a subsequent examination after he returned home, Philippine health officials said Saturday.

Egypt archaeologists find ancient writer's tomb

Egypt's minister of antiquities says a team of Spanish archaeologists has discovered two tombs in the southern part of the country, one of them belonging to a writer and containing a trove of artifacts including reed pens ...