June R&D Round UpJune 4, 2010 By: Melanie Martella, Sensors
This month we've got the ability to print simple field-effect transistors using nanotube-laden ink and an ink-jet printer and an endoscope with a tiny image sensor to enable in-vivo cancer diagnoses.
Nanotubes for Printed Electronics
Carbon nanotubes have attracted a lot of attention because of their potential use in sensors and other electronics. Now, researchers have used an ink-jet printer to print nanotube-based field-effect transistors (FETs). The scientists, Robert Vajtai and Pulickel Ajayan of Rice University, Eduardo Gracia-Espino of the Instituto Potosino de Investigacion Cientifica y Tecnologica, Mexico; Giovanni Sala, Flavio Pino, Niina Halonen, Jani Mäklin, Géza Tóth, Krisztiçn Kordás and Heli Jantunen of the University of Oulu, Finland; Juho Luomahaara, Panu Helistö and Heikki Seppä of the VTT Technical Research Center of Finland; and Mauricio Terrones of the Universidad Carlos III of Madrid, developed custom inks containing single-walled carbon nanotubes (SWNTs) that enabled them to print layers of nanotubes onto a substrate. Further, by adding different functional groups to the nanotubes they could adjust their conductive or insulating properties. By printing source, gate, drain, and conductive layers, the researchers found that they could print simple, functional electronic circuits onto a flexible substrate. (For more details, including an excellent diagram, read "Outstanding in their field effect" from the Rice University News Service.)
Detecting Tumors Even Earlier
Diagnosing a lump as cancerous or benign is typically neither fun nor speedy. Biopsies are stressful and painful and then comes the waiting for the results. Based on work conducted at Fraunhofer IPMS, doctors may get a tool to diagnose tumors in-vivo. The researchers have designed and built a tiny microscope—using a MEMS-based image recorder and a microscanner mirror—that sits at the end of an endoscope and allows the doctor to examine the target cells in situ. The endoscope is placed in the target tissue. An optical fiber transmits laser light to the microscanner mirror at the tip of the endoscope where the laser beam is deflected to illuminate the target cells. A glass-fiber bundle in the endoscope's tip then transmits the reflected light to the external image recorder. By coupling the image sensor and mirror position information, the system can create a 2D image. The MEMS-based image sensors can magnify very small objects without requiring large lenses. The combination of the sensor and microscanner mirror allows the system to achieve 10 µm resolution, in fact.
Sensors Expo is Coming!
Next week, from Monday June 7 through Wednesday June 9, I'll be attending Sensors Expo & Conference at the Donald E. Stephens Convention Center in Rosemont, IL. And if the sensor technology isn't enough to lure you, this year the show is collocated with the ESC-Chicago. If you'll be there too, please say hello! Stay tuned to next week's newsletter to learn which products have won the 2010 Best of Sensors Expo Awards.
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