Multi-Physics, Multi-Functional Nano-Engineered Composites for Structural Health Monitoring

Period of Performance: 11/02/2010 - 11/02/2012


Phase 2 STTR

Recipient Firm

Metis Design Corp.
205 Portland St Array
Boston, MA 02114
Principal Investigator

Research Institution

Massachusetts Institute of Technology
77 Massachusetts ave
Cambridge, MA 02139
Institution POC


ABSTRACT: Composite materials are increasingly adopted into Aerospace application due to their superior specific strength/stiffness, resistance to fatigue and ability to reduce part-count. Furthermore, it has been demonstrated that by introducing carbon nanotubes (CNTs), multi-functional capabilities can be achieved by virtue of their high conductivity and piezoresistive nature. During the proposed research, Metis Design Corporation (MDC) will collaborate with MIT to demonstrate multi-physics, multi-functional nano-engineered composites for structural health monitoring (SHM). This system will not only introduce passive/active SHM/NDE capabilities for diagnostics/prognostics via the aligned in-situ grown CNTs, but have no impact on structural weight while increasing the delamination toughness. Following the successful Phase I effort demonstrating the ability to characterize damage state in small laminates using resistance measurements, the Phase II tasks will focus on integrating multiple detection methods and further scaling/maturing the technology. Initial tasks will aim to optimize direct-write electrode spacing with respect to detection resolution and develop algorithm compensation for strain, thermal and hysteresis effects. The next set of tasks will involve the development and assimilation of acoustic emission (AE) and thermographic methods within the overall scheme. Finally, each of the developed technologies will be demonstrated on a large (~1x1 m) built-up specimen subject to impact damage. BENEFIT: There are tremendous commercialization opportunities for the proposed technology. Essentially these in-situ grown CNTs can enable diagnostic and prognostic capabilities for traditional composite structures through conventional SHM and NDE methods, including acoustic emission, thermography and resistance measurements. SHM technologies have the potential for many economic benefits in a broad range of commercial and defense markets, ranging from military or civil aircraft to spacecraft and naval vessels. The first major benefit is that SHM eliminates the need for scheduled inspections. A second major economic benefit is that a continuously monitoring system would allow for the use of the much more efficient condition based maintenance (CBM) design methodology of a structure, otherwise known as need-based repair. A third benefit is the increased service time of the structure. Finally, an SHM system could have a significant financial impact if it is able to detect the need for maintenance before a catastrophic failure, potentially saving lives and a costly vehicle. The first obvious target is the military sector, where one of these systems can reduce the manpower needed for inspection, as well as up to 30% of the maintenance costs. Another important aerospace market would be to facilitate launch/no-launch decisions for expendable launch vehicles (ELV), and enable quick turn-around times for reusable launch vehicles (RLV). Airlines that chose to use these systems would be able to reduce the quantity and duration of required inspections, giving them the opportunity cost to capture profit due to more up-time. MDC has a clear path towards commercialization for the proposed technology through our industry partners Boeing & Lockheed. These large aerospace integrators are perfectly positioned to deploy this technology for military and commercial air and space applications. They have both already expressed explicit interest in this technology and have committed to both participate in the Phase II using IR&D funding as well as contribute a separate investment to MDC/MIT in order to further customize and mature this technology for their specific applications. MDC has already worked closely with Boeing in the past to serve as a transition partner for SHM-related technologies, to market, distribute and integrate these products within Aerospace and other platforms. Currently, MDC fabricates prototype systems in-house by outsourcing many of the components (sensors, circuit board, casing, etc) and then integrating them in-house, however for larger quantities of devices MDC has negotiated costs with a professional electro-mechanical assembly company who offers a turn-key product delivery. The primary revenue stream for MDC will be royalties from the patented technology, however in addition MDC will capture revenue from supplying, customizing and maintaining the software to interface with the system. Initially these products will be marketed towards the air and space industry, but eventually will be more broadly diffused.