Single Wall Carbon Nanotube-Based Structural Health Monitoring Sensing Materials
A.N. Watkins, J.L. Ingram, J.D. Jordan, R.A. Wincheski, J.M. Smits and P.A. Williams
NASA Langley Research Center, US
Keywords: Carbon nanotube devices, sensors, multifunctional materials, vehicle health monitoring
Single-wall carbon nanotube (SWCNT)-based materials represent the future aerospace vehicle construction material of choice based primarily on predicted strength-to-weight advantages and inherent multifunctionality. As such, it is prudent to pursue the development of SWCNT-based sensing strategies that can be integrated into structural material systems at any point in the component fabrication process, and in doing so produce multifunctional materials that will create further gains in payload capacity. We are exploiting the multifunctioanlity of SWCNTs to construct sensors capable of measuring several parameters related to vehicle structural health (i.e., strain, pressure, temperature, etc.). The structural health monitor (SHM) is constructed using conventional electron-beam and photolithographic techniques to deposit a series of electrodes separated by a few microns. SWCNTs are then deposited and aligned between the electrodes using various self-assembly techniques. Initial prototypes were constructed on silicon substrates and the resistance of the deposited SWCNTs was measured as a function of temperature. Several new strategies are currently being investigated to increase the strain sensitivity of the SHM. These include new circuit architectures providing an anchor for the deposited SWCNTs and the use of flexible, plastic-based substrates. These advances will make a SWCNT-based SHM that is surface-mountable and multifunctional (large arrays) a near-term achievable goal.
Nanotech 2004 Conference Technical Program Abstract