BEGIN:VCALENDAR
VERSION:2.0
PRODID:-//Talks.cam//talks.cam.ac.uk//
X-WR-CALNAME:Talks.cam
BEGIN:VEVENT
SUMMARY:DETECTION OF VOLATILE ORGANIC COMPOUNDS USING PIEZORESISTIVE MICRO
 CANTILEVER SENSORS WITH METAL ORGANIC FRAMEWORKS - Professor Peter J. Hesk
 eth\, School of Mechanical Engineering\, Georgia Institute of Technology\,
  Atlanta\, GA 30332
DTSTART:20131218T133000Z
DTEND:20131218T143000Z
UID:TALK49494@talks.cam.ac.uk
CONTACT:Dr Myriam Ouberai
DESCRIPTION:Metal Organic Frameworks (MOFs) are a new class of nanoporous 
 materials which have a high surface area\, thermal/chemical stability and 
 a tailorable pore size. HKUST-1 MOF was selected due to large internal sur
 face area\, excellent stability and known properties.  Mechanical strain i
 s generated upon adsorption of analytes into the MOF\; it is proportional 
 to concentration and is a function of adsorbed species. Piezoresistive mic
 rocantilever sensors are microfabricated devices that are highly sensitive
  to surface strain due to doped single crystal silicon regions. A thin fil
 m of HKUST-1 was grown at room temperature using layer-by-layer techniques
 .  Changes in resistance generated by surface strain can be measured with 
 a high degree of accuracy using a Wheatstone bridge and simple instrumenta
 tion. Dry nitrogen was used as a carrier gas to expose devices to varying 
 concentrations of twelve different VOC’s.  Results show that stress-indu
 ced piezoresistive microcantilever array sensors with MOF coatings can pro
 vide a highly sensitive and reversible sensing mechanism for water vapor a
 nd methanol.  Characteristic response features allow discrimination based 
 on shape\, response time constants and magnitude of response for other VOC
 ’s. The microcantilever sensors were shown to be durable\, reliable and 
 stable in long term testing despite being exposed to many different analyt
 es. This work shows a promising new technology for a next generation senso
 rs for gas monitoring. The key advantages of this type of sensor are the h
 igher sensitivity with a nano-porous MOFs\, reversible response\, single c
 hip sensing system and low power operation.\n\nEveryone is welcome.
LOCATION:MRC Seminar Room M208\, Cavendish Laboratory\, Department of Phys
 ics
END:VEVENT
END:VCALENDAR