Caibin Xiao

Theory and practice of ubiquitous quantitative chemical analysis using conventional computer optical disk drives.

We demonstrate a new attractive approach for ubiquitous quantitative chemical or biological sensing when analog signals are acquired from conventional optical disk drives, and these signals are used for quantitative detection of optical changes of sensing films deposited on conventional CD and DVD optical disks. Our developed analytical model of the operation of this Lab-on-DVD system describes the optical response of sensing films deposited onto the read surface of optical disks by taking into account the practical aspects of system performance that include possible reagent leaching effects, water sampling (delivering) efficiency, and possible changes of the film morphology after water removal. By applying a screen-printing process, we demonstrated a laboratory-scale automated production of sensing films with an average thickness of approximately 10 microm and a thickness relative standard deviation of <3% across multiple films. Finally, we developed a system for delivery of water-sample volumes to sensing films on the disk that utilized a multifunctional jewel case assembly.

Quantitative Chemical Analysis using DVDs and Conventional Computer Optical Disk Drives

In optical indicator-based sensing, it is critical to have an inexpensive and portable optical reader that can be operated as a handheld or remotely activated device. With such a reader and an array of indicator films, one can analyze drinking water and air during an overseas trip, water and air near an industrial plant, or water in a swimming pool in a backyard. For these and many other applications, a universal optical reader is very attractive. To eliminate the need to develop and manufacture at a low cost a dedicated optical measurement system, we have developed a new approach for quantitative chem/bio sensing using conventional optical disk drives. We extract analog signals from an optical disk drive and use these signals for quantitative detection of optical changes of sensing films deposited on conventional CD or DVD optical disks.