{"339571":{"#nid":"339571","#data":{"type":"event","title":"Ph.D. Defense by Mengdi Luo","body":[{"value":"\u003Cp\u003EPTFE PhD Defense \u2014 \u003Cstrong\u003EMengdi Luo\u003C\/strong\u003E\u003C\/p\u003E\u003Cp\u003ETitle: \u003Cstrong\u003EMaterials and Microfabrication Approaches for Completely \u003C\/strong\u003E\u003Cbr \/\u003E\u003Cstrong\u003EBiodegradable Wireless Micromachined Sensors\u003C\/strong\u003E\u003C\/p\u003E\u003Cp\u003EDate: Friday, November 7, 2014\u003Cbr \/\u003ETime: 2:10 pm\u003Cbr \/\u003ELocation: MRDC 3515 (Hightower Conference Room)\u003C\/p\u003E\u003Cp\u003ECommittee:\u003Cbr \/\u003EDr. Mark G. Allen, ECE (Advisor)\u003Cbr \/\u003EDr. Oliver Brand, ECE\u003Cbr \/\u003EDr. Zhiqun Lin, MSE\u003Cbr \/\u003EDr. Preet Singh, MSE\u003Cbr \/\u003EDr. Donggang Yao, MSE\u003C\/p\u003E\u003Cp\u003E\u003Cstrong\u003EAbstract:\u003C\/strong\u003E\u003C\/p\u003E\u003Cp\u003EImplantable sensors have been extensively investigated to facilitate \u003Cbr \/\u003Ediagnosis or to provide a means to generated closed loop control of therapy \u003Cbr \/\u003Eby yielding in vivo measurements of physical, chemical and biological \u003Cbr \/\u003Esignals. MEMS technology has demonstrated significant value in this \u003Cbr \/\u003Eapplication mainly due to their micro-scale size, low weight, low power \u003Cbr \/\u003Econsumption, potential for low fabrication cost, superior functionality or \u003Cbr \/\u003Eperformance, and can be combined with biotechnology and molecular biology. \u003Cbr \/\u003EAmong those, biodegradable sensors which degrade gradually after they are no \u003Cbr \/\u003Elonger functionally needed exhibit great potential in the acute or \u003Cbr \/\u003Eshorter-term medical diagnosing and sensing due to the advantages of (a) \u003Cbr \/\u003Eexclude the need to a secondary surgery for sensor removal, and (b) reduce \u003Cbr \/\u003Ethe risk of long-term infection.\u003C\/p\u003E\u003Cp\u003EThe objective of this research is by investigating the biodegradable \u003Cbr \/\u003Ematerials and developing proper fabrication process, to design and \u003Cbr \/\u003Echaracterize microfabricated RF wireless pressure sensors that are made of \u003Cbr \/\u003Ecompletely biodegradable materials and degrade at time-controlled manner. In \u003Cbr \/\u003Eorder to do that, we explore this study in four areas: (1) designing the \u003Cbr \/\u003Esensors that operate wirelessly made of biodegradable materials; (2) \u003Cbr \/\u003Einvestigating the biodegradable materials in the application of implantable \u003Cbr \/\u003Ebiodegradable wireless sensors to achieve different degradation life time; \u003Cbr \/\u003E(3) developing a new fabrication process that allow handling delicate \u003Cbr \/\u003Ebiodegradable materials; and (4) testing the pressure response functionality \u003Cbr \/\u003Eand studying the degradation behavior of the wireless biodegradable pressure \u003Cbr \/\u003Esensors.\u003C\/p\u003E\u003Cp\u003EIn this work, two categories of completely biodegradable pressure sensors \u003Cbr \/\u003Eare fabricated and characterized. (1) Slow degradation sensor that made of \u003Cbr \/\u003Epoly(L-lactic acid) (PLLA) and zinc(Zn) or zinc\/iron (Zn\/Fe)-couple; (2) \u003Cbr \/\u003Erapid degradation sensors that utilizes poly(lactic-co-glycolic acid)\/poly \u003Cbr \/\u003E(vinyl alcohol) (PLGA\/PVA) \u201cshell-core\u201d structure as the dielectrics and Zn \u003Cbr \/\u003Eor Zn\/Fe couple as the conductors. All the sensors show three stages of \u003Cbr \/\u003Ebehavior in vitro: equilibration stage, functional lifetime, and performance \u003Cbr \/\u003Edegradation. During the functional life time, most successful sensors \u003Cbr \/\u003Eexhibit fully stable functionality: relatively steady resonant frequency and \u003Cbr \/\u003Eslight decrease of quality factor with zero applied pressure, as well as \u003Cbr \/\u003Ecomparable sensitivities at different time points. The slow degradation \u003Cbr \/\u003Esensors which demonstrate functional lifetimes of 4 to 15 days, are expected \u003Cbr \/\u003Eto fully degrade after 2 years based on the degradation of the polymer \u003Cbr \/\u003Epackage. The rapid degradation sensors exhibit functional lifetimes of \u003Cbr \/\u003Eapproximately 1 day and degrade completely with 26 days, demonstrating a \u003Cbr \/\u003Ehigher functional time ratio of 4%.\u003C\/p\u003E","summary":null,"format":"limited_html"}],"field_subtitle":"","field_summary":"","field_summary_sentence":[{"value":"Materials and Microfabrication Approaches for Completely  Biodegradable Wireless Micromachined Sensors"}],"uid":"28077","created_gmt":"2014-11-03 16:26:42","changed_gmt":"2016-10-08 02:10:03","author":"Danielle Ramirez","boilerplate_text":"","field_publication":"","field_article_url":"","field_event_time":{"event_time_start":"2014-11-07T13:10:00-05:00","event_time_end":"2014-11-07T15:10:00-05:00","event_time_end_last":"2014-11-07T15:10:00-05:00","gmt_time_start":"2014-11-07 18:10:00","gmt_time_end":"2014-11-07 20:10:00","gmt_time_end_last":"2014-11-07 20:10:00","rrule":null,"timezone":"America\/New_York"},"extras":[],"groups":[{"id":"221981","name":"Graduate Studies"}],"categories":[],"keywords":[{"id":"106731","name":"PhD Defense; graduate students"}],"core_research_areas":[],"news_room_topics":[],"event_categories":[{"id":"1788","name":"Other\/Miscellaneous"}],"invited_audience":[{"id":"78771","name":"Public"}],"affiliations":[],"classification":[],"areas_of_expertise":[],"news_and_recent_appearances":[],"phone":[],"contact":[],"email":[],"slides":[],"orientation":[],"userdata":""}}}