CAREER: Low-cost Arrayed Gas Sensors Using Inkjet-printed Organic Transistors

University Of California-Berkeley, Berkeley CA

Investigators

Abstract

In recent years, there have been some initial demonstrations of organic transistor-based gas sensors. These initial demonstrations have established that sensors using different organic active layers show different responses to different odors and gas-phase toxins. While individually these sensors do not offer much specificity, they may potentially be arrayed to form an electronic nose, offering high sensitivity and selectivity to a wide range of analytes, in a manner analogous to a dog's nose. In particular, it may be possible to form ultra-low cost sensors suitable for such cost-sensitive applications as distributed environmental monitoring and content monitoring of food and pharmaceutical packages. This may be achieved by fabricating the entire organic sensor array using a low-cost printing technology on a low-cost flexible substrate. Such a technology will usher in an era of unprecedented public safety, reduced product wastage, and proactive environmental protection since the sensors may be deployed in ubiquitous sensor networks due to their extremely low cost and flexibility. Within this proposal, the investigators will develop the device and materials technologies necessary for an arrayed sensor system, and will use these to demonstrate an integrated low-cost electronic array offering high sensitivity and specificity. Specifically, they will develop a manufacturing technology for forming these sensors on low cost plastic substrates entirely using inkjet printing. Diverse families of active layer materials will be arrayed to form high specificity sensor arrays on low-cost plastic substrates, ensuring low cost while simultaneously providing high specificity and sensitivity. An undergraduate and a graduate student will be involved in performing this work. The interdisciplinary nature of this work will further the knowledge base of both students. In particular, the mentoring of the undergraduate student will be emphasized through critical review programs and experimental design and metrology tutorials. The results of this proposal will also be used in a University-sponsored high-school outreach program. High-school students will be invited to visit the laboratory and to gain hands-on experience with inkjet-based circuit fabrication. This will increase the level of interest in science and engineering among local high-school students. Furthermore, the investigators will devote much effort to enabling transfer of the technology to researchers in industry and other academic groups through publications, web-based technology dissemination, and industrial interactions. An integral part of the educational component of this program focuses on the recruitment and retention of underrepresented minority groups. The PI will travel regularly to the eastern and southeastern United States to meet with minority students at HBCU's to advise on opportunities for advanced studies in EECS at Berkeley. A representative from BGESS (the organization of the Black Graduate Engineering and Science Students at UC Berkeley) will accompany him to facilitate this. This activity will be used to substantially increase the enrollment and retention of underrepresented groups in EECS at Berkeley.