• PDF / 466,945 Bytes
• 43 Pages / 439.37 x 666.142 pts Page_size
• 58 Downloads / 290 Views

DOWNLOAD

REPORT

---

Abstract This chapter intends to provide an introduction to and a very brief summary of the principal categories of color sensors and of their applications, both relatively little known to the general public. First, an introduction describes the background of the topic(s) and the overall context. The main differences between two major but complementary techniques, colorimetry and spectrometry, will be presented here, as well as a quick summary of the scientific, technical, and industrial applications of color sensing. The second section will summarize the basic operational principles and architectures of color sensors realized in silicon. Although stand-alone detectors will also be described and discussed, the main focus will be on solid-state microsensors which can ideally be monolithically integrated together with signal processing circuits onto the same chip as “smart sensors” or intelligent microsystems. First, sensors realized only in monocrystalline silicon are summarized, followed then by those fabricated in other materials, with amorphous silicon and its alloys as the key players in this latter category. Finally, the chapter ends with the sections devoted to Conclusions and References. This chapter presents only a few of the most relevant aspects related to color sensors and examples of their practical applications. It is, in fact, an extensively abbreviated version of a much more detailed and exhaustive review dedicated to both color sensing and microspectrometry, and which is presently in preparation for future submission to Springer Verlag. Keywords Smart sensors • Color filter array (CFA) • Two-junction color sensors • Triple-junction color sensors • Thin film color sensors

P.D. Puiu (*) School of Electrical and Electronic Engineering, Nanyang Technological University, 50 Nanyang Avenue, Singapore, Republic of Singapore 639798, e-mail: [email protected] W. Fritzsche and J. Popp (eds.), Optical Nano- and Microsystems for Bioanalytics, Springer Series on Chemical Sensors and Biosensors (2012) 10: 3–46 DOI 10.1007/978-3-642-25498-7_1, # Springer-Verlag Berlin Heidelberg 2012

3

4

P.D. Puiu

Contents 1 Introduction—The Color Sensor: Necessity or Just a Curiosity? . . . . . . . . . . . . . . . . . . . . . . . . . . 1.1 Chemistry . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1.2 Life Sciences . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1.3 Food and Beverages Industry . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1.4 Scientific, Technical, and Industrial Applications of Color Sensing . . . . . . . . . . . . . . . . . 2 Monolithic Color Sensors . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2.1 Basics of Solid-State Color Sensing . . .