1 Copyright © 2012 by ASME Proceedings of the ASME 2012 Conference on Smart Materials, Adaptive Structures and Intelligent Systems SMASIS2012 September 19-21, 2012, Stone Mountain, Georgia, USA SMASIS2012-8200 SOLID-STATE DYE SENSITIZED OPTOELECTRONIC CARBON NAOTUBE-WIRES: AN ENERGY HARVESTING DAMAGE SENSOR WITH NANOTECHNOLOGY APPROACH Mohammed Jasim Uddin, Tarik J. Dickens, Jin Yan, David O. Olawale, Okenwa I. Okoli High-Performance Materials Institute, FAMU – FSU College of Engineering, 2525 Pottsdamer St., Tallahassee, FL-32310, USA Federico Cesano Nanostructured Interfaces and Surfaces (NIS), Centre of Excellence, Department of Chemistry IFM, University of Turin, Via P. Giuria 7, Turin, 10125, Italy ABSTRACT A novel preparation method of solid state photovoltaic carbon nanotubes (CNT) yarns has been successfully developed by depositing and grafting TiO 2 thin films on CNT yarn substrates using a simple sol–gel method and designed for use in structural health monitoring (SHM) applications. The interaligned, ultrastrong and flexible CNYs display excellent electrical conductivity, mechanical integrity and their catalytic properties have been successfully used as working and counter electrodes. The TiO 2 nanoparticles have been found to form a homogeneous thin film on the yarn surface, which shows efficient photovoltaic properties with remarkable stability when exposed to simulated solar light (AM 1.5). The yarns’ structure is not altered upon sol-gel treatment and light exposure. The TiO 2 film is firmly anchored and the photovoltaic performance is retained even after multiple irradiation cycles. This preparation technique can also be applied to CNT yarn reinforced composite for an innovative in-situ and real-time self damage-sensing properties with infused triboluminescent (TL) materials. INTRODUCTION Titanium dioxide (TiO 2 ), an inexpensive, non-toxic and biocompatible material, is one of the most important and widely investigated photocatalyst [1-3], because of its potential application in dye-sensitized solar cells (DSSCs)[4] and in decomposition of various environmental pollutants[3]. Development of TiO 2 based thin films anchored to supporting materials with large surface areas would be of great significance, not only to avoid the disadvantages of filtration and suspension of fine photocatalyst particles[5], but also to lead high photoconversion efficiency[6]. DSSCs are attracting extensive interest in the scientific and industrial fields because of their low cost and high energy conversion efficiency[4, 7-9]. The conversion efficiency of planar DSSCs has been reported to reach 12.1% with platinized FTO (fluorine doped tin oxide) positive electrodes[10, 11]. The counter electrode (CE) exhibits a key factor in receiving electrons from the outer circuit and reduction of the electrolyte (I 3 - to I - )[12-14]. The conventional DSSCs form factor consist of rigid FTO glass, which has restricted adaptability during transportation, installation and application[9]. Enhancing DSSCs’ adaptability necessitates the challenging improvement of cell flexibility and stability[9, 15, 16]. However, photovoltaic wires have opened up an innovative feasibility for cost-effective and scalable solar energy harvesting systems with potential textile applications[17, 18]. A few research outcomes have recently been reported in the field of organic-based photovoltaic devices[19-21]. Several recent reports discussed the fabrication of fiber-shaped DSSCs using metal wires as working electrodes (WE) in combination with solid electrolytes and displayed energy conversion efficiencies near 0.06%[9, 16]. Some reports indicate that the efficiency could be increased if the DSSCs are assembled with liquid electrolyte and glass cladding, [8, 14, 18, 22-24] which yields limited sustainability during transportation and installation. The rapidly developing optoelectronic industry, especially in the