Energy-Based Vibration Control System for Load-Bearing Skin Structures
Summary:
With the help of BMDO SBIR funding, Quality Research, Development & Consulting, Inc. (QRDC;Chaska, MN) has developed a “smart skin,” called the Energy-Based Smart Skin Structure™ (EBS3), that can control the vibration and acoustic energy by actively channeling energy flow to strategically-placed “energy-sinks.” EBS3 could control vibration and noise in anything from home appliances and aircraft to automobiles and offshore oil-platforms. QRDC has granted an exclusive license to Smart Skin, Inc. (SSI), which plans to start marketing EBS3-based products by 2001.
Technology Description:
Quality Research, Development, & Consulting, Inc. (QRDC; Chaska, MN) has developed a “smart skin,” called the Energy-Based Smart Skin Structure™ (EBS3), that can control vibration and acoustic energy by actively channeling the energy flow that pervades the structure.
EBS3 is based on earlier DARPA-funded work on a patented QRDC technology called Vibration Control by Confinement™ (VCC), which suppresses noise and vibrations by controlling energy flow. Through the use of embedded actuators and sensors, it diverts vibrational energy away from critical areas to strategically-placed energy sinks. With a small amount of input energy directed to controllers, VCC attenuates the motion of critical regions of a vibrating system. On an aircraft or missile, for instance, surface sensors may be protected as vibration can be diverted to sinks as close as a few millimeters or as far away as the end of the vehicle.
VCC demonstrates a 90 to 98 percent improvement over passive dampening techniques—such as dampers, isolators and absorbers—depending on the type of vibration and structure. While passive devices are lower in cost, the dramatic performance advantages of VCC will be useful in many applications, particularly weight-critical aerospace structures (passive dampening devices tend to be very bulky). VCC has also shown performance gains over active vibration suppressors, while remaining cost-competitive. In addition, VCC is much more efficient than active dampening technology, since it only uses enough energy to redirect vibrations to a sink, rather than completely canceling out the vibration.
Although QRDC is retrofitting VCC to existing surfaces, the BMDO-funded work focuses on developing an entirely new VCC-enabled “smart-skin,” EBS3. The skin is a multi-layer composite with sensors and a layer of embedded actuators made from lead (Pb) zirconium titanate (PZT)—a pizoelectric material that changes its dimensions when a voltage is applied and produces a charge when pressure is applied. In addition, controllers are used to enable the system. The BMDO prototype of the skin is 0.25'' thick, which should easily shrink to about a millimeter in future prototypes (and with more far-reaching plans to someday make micro- and nanometer-scale skins). As with all piezoelectric ceramics, this material has the ability to work
in temperatures from -40° degrees C to 160° degrees C, and the controller elements can be fitted to work with any materials needed for special environmental conditions.
MDA Origins:
BMDO SBIR Phase II work is being undertaken to build a fully functional prototype of EBS3. An EBS3 for missiles and aircraft would provide the aerodynamic surfaces required for more efficient flight as well as for protection against aerodynamic loads and threatening airborne elements. Such a material would also protect sensitive missile payloads and instrumentation from the high vibration levels inherent in missile flight. BMDO’s developments of thinner and lighter materials for missile components necessitates dampening materials, as such materials have higher vibrational levels.
Spinoff Applications:
EBS3 could control noise and vibration in anything from home appliances to automobiles and offshore oil platforms. One ideal use would be for military aircraft. The company foresees a potential $1.9 to $5 billion market for the U.S. military sector alone. Aircraft might be able to shed heavy shock-absorbing armor, lowering fuel costs. Plus, as EBS3 can enhance aerodynamics of the aircraft by contracting or expanding in response to the electrical impulses sent to the actuators. A smart skin can also continuously monitor the health of the aircraft systems and subsystems. For the interior, a smart skin would reduce cabin noise and vibration. The early estimated cost of retrofitting an aircraft would be somewhere between $50,000 to $100,000. The smart skin would also have similar benefits to submarines, ships, commercial airlines, and automobiles.
Smart skins may also be used indoors as well. Orchestra halls might use this skin as a form of wallpaper to create places that resonate with perfect sound. The acoustics of a room can be modified with a flick of the switch. Smart skins may also be used in the clean rooms or quality inspection rooms of processing plants where even the smallest disturbances are unacceptable.
Commercialization:
QRDC has granted an exclusive license to Smart Skin, Inc. (SSI), which will market products while QRDC will continue the R&D effort. SSI is now evaluating potential markets and is planning to enter the commercial arena sometime between 2001 and 2003. The company plans to raise between $20 and $30 million in start-up investments.
U.S. Steel-MINNTAC is also working with QRDC to bring the material to commercial feasibility for use as high-performance vibrating screens used by the processor industry. The company predicts it could generate $5 million in the first two to three years of production, with an international market predicted to be over $2 billion.
Company Profile:
Founded in 1992, QRDC is currently based in Chaska, MN and has nine employees. The company’s mission is to become the dominant supplier of active noise and vibration control products and technologies. In addition to EBS3 research and development, QRDC is also commercializing other aspects of the VCC technology, including the development of smart isolation systems for electronic racks, smart isolation mounts for weapons systems, and smart isolation systems for submarine sonar. QRDC was highlighted in 2000 as one of Fortune Small Business’s top 25 Hot New Companies to Watch.
Smart Skin, Inc. (SSI) was incorporated in November 2000 and has a full-time CEO who is responsible for raising capital, developing a management team and overseeing the growth of the company. SSI has formed a board of directors whose members have extensive business background and fundraising experience. Based on the current plans, SSI will hire between 15 and 30 employees by the end of 2001. The company is currently presenting its business plan to large companies and investors and plans to initiate an initial public offering in 2003 or 2004.
Contact Information:
Dr. Daryoush Allaei (principal investigator)
QRDC, Inc.
PO Box 562
Chaska MN 55331-0562
Tel:952-556-5205
Fax:952-556-5206
email: dallaei@qrdc.com
web: www.qrdc.com
Dan Woodbury (director of sales and marketing)
Tel:952-556-5205
Fax:952-556-5206
email: dwoodbury@qrdc.com
James I. Finley, President/CEO
Smart Skin, Inc.
125 Columbia Court North
Chaska MN 55318-2348
Tel:952-556-5205
Fax:952-556-5206
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