Innovative MEMS Sensors for Biological Applications Researched and Developed at The City College of New York

with Ioana Voiculescu,
Associate Professor, The City College of New York

April 20th, 3:00 pm, Goodwin Hall 440
(contact Hope House for webinar link)

 In this seminar two devices fabricated with microelectromechanical systems (MEMS) technology and their applications will be presented:

(1) MEMS Biosensor with Integrated Impedance Spectroscopy and Gravimetric Measurements for Water Toxicity Testing

This presentation describes the design, fabrication and characterization of a multiparametric biosensor based on live mammalian cells. This biosensor combines two biosensing techniques; resonant frequency measurements and electric cell-substrate impedance sensing (ECIS) on a single chip. The biosensor can simultaneously perform in real-time two different types of electric measurements on the same mammalian cell monolayer: (1) monitoring the resonant frequency values of a quartz crystal microbalance (QCM) resonator that will give information about the progression of cells adhesion and cell viscoelasticity and, (2) recording the impedance spectra of the cells, that will report on cell adhesion progress, shape, growth, motility and viability. The sensor is based on the innovative placement of the working microelectrode for ECIS technique as the upper electrode of a QCM resonator. Bovine aortic endothelial cells (BAECs) with different densities were used as sensitive cells. This lab on chip was demonstrated to indicate low concentration of toxicants. The responses of BAECs to toxic samples occurred 5 to 20 minutes after the cell contamination, depending on the type of chemicals and concentrations. A highly linear correlation between signal shifts and chemical concentrations was demonstrated for each toxicant.

(2) Wearable and Stretchable Piezoelectric Powergenerator for Skin Applications

The presentation describes a stretchable piezoelectric power generator that is intended to harvest energy. The powergenerator was fabricated from zinc oxide (ZnO) piezoelectric thin film embedded in polymer materials. The microfabricated powergenerator will be attached on the skin and stretched by the natural movements of arms, legs or neck. We expect that energy harvested by this device will be able to power wearable skin sensors. In the presentation this device fabrication will be described, and the testing method will be also discussed along with the output power from this device. The device could be also used as smart skin sensitive to touching or a pressure sensor.

Ioana Voiculescu graduated with a Ph.D. in Mechanical Engineering from Politehnica University Timisoara, Romania and she obtained the second doctorate degree, Sc.D., in Mechanical Engineering from The George Washington University. She conducts research for chemical and biomedical sensors, actuators, and microsystems based on microelectromechanical system (MEMS), micro total analysis system (or “Lab-on-a-chip”) and semiconductor technologies. She received several research grants funded by the National Science Foundation (NSF) and U.S. Army Research Office. She also worked two years at U.S. Naval Research Laboratory (NRL) in Washington DC. At NRL she conducted research for several Complementary Metal Oxide Semiconductor (CMOS)-Microelectromechanical Systems (MEMS) devices used for detection of explosives and chemical agents such as: a resonant microcantilever beam sensor for the detection of chemical warfare agents, and a micromachined preconcentrator for enhancing trace detection of explosives. She has three US patents on her name and more than 30 peer reviewed journal papers. She also recently edited a book; “Nanocantilever beam, fabrication and applications”