1,720,992 research outputs found
Configurable 3D Nanoscale High Aspect Ratio Pillars for Surface-Enhanced Raman Spectroscopy
No full textProgramming of wicking behavior of hydrogel and paper-based microfluidic device
Full text linkPaper-based microfluidics (μPADs) have been a popular choice as lateral flow tests (LFTs) platform for diagnostic purpose because of its ease of use, speed, affordability, and spontaneous fluid transport based on an intrinsic property of material. Recent developments have rapidly increased the analytical capacity and complexity of μPADs through structural enhancements and flow control techniques. In doing so, novel wicking material such as hydrogel is introduced for additional functionality and contribute to structural complexity.
The design to accommodate both the functionality and complexity of the structure is, thus, getting more and more complicated, but the process is still based on a time-consuming “estimate and check” method, which requires multiple iterations. A model that can effectively adapt properties of different wicking materials in the device and predict a resulting collective flow behavior is highly desirable with growing number of constituents and capability of μPADs.
Here, the pre-storage capability of reagents in hydrogel is investigated to understand the role in μPADs and a series of experiments were conducted to identify key flow parameters to build a computational model for the flow behavior prediction. Electrical circuit analogies derived from Darcy’s law and Washburn equation are used to model the fluidic behavior of μPADs. The computational model depicts flow behavior in two connected different wicking materials, paper and hydrogel, and will be a useful tool to optimize the design process and reduce tunable time to produce a functional paper-based microfluidic device. Furthermore, the functionality of the hydrogel incorporated paper-based microfluidic device was demonstrated in the LFT format to detect glucose in sample.Submission published under a 24 month embargo labeled 'Closed Access', the embargo will last until 2018-12-01The student, Sumin Kim, accepted the attached license on 2016-10-29 at 00:27.The student, Sumin Kim, submitted this Thesis for approval on 2016-10-29 at 00:37.This Thesis was approved for publication on 2016-11-30 at 14:16.DSpace SAF Submission Ingestion Package generated from Vireo submission #10208 on 2017-02-28 at 14:41:17Made available in DSpace on 2017-03-01T17:01:08Z (GMT). No. of bitstreams: 2
KIM-THESIS-2016.pdf: 1854904 bytes, checksum: 2ba3b4092a1c006adb1a7e4d083679a6 (MD5)
LICENSE.txt: 4206 bytes, checksum: 748af309a6edb5817381393df4718649 (MD5)
Previous issue date: 2016-11-30Embargo set by: Seth Robbins for item 98678
Lift date: 2019-03-01T17:02:22Z
Reason: Author requested closed access (OA after 2yrs) in Vireo ETD systemEmbargo set by: Seth Robbins for item 98678
Lift date: 2019-03-01T17:03:32Z
Reason: Author requested closed access (OA after 2yrs) in Vireo ETD systemEmbargo set by: Seth Robbins for item 98678
Lift date: 2019-03-01T17:05:02Z
Reason: Author requested closed access (OA after 2yrs) in Vireo ETD systemEmbargo set by: Seth Robbins for item 98678
Lift date: 2019-03-01T17:06:55Z
Reason: Author requested closed access (OA after 2yrs) in Vireo ETD systemLimited Restriction Lifted for Item 98678 on 2019-03-02T10:15:18Z
Portable biomedical measurement devices: MoboSens and impedance sensing systems
Full text linkHuman health has become a very important topic as society pays more attention to the people’s quality of life. Therefore, wearable devices with the capability of monitoring various human health indexes and detecting environmental pollution metrics are in great demand.
In this thesis, two methods will be discussed in detail. One method that has been developed to perform the tests is called electrochemical sensing, ‘MoboSens’. It uses a smartphone as its sensing platform with an integrated plug-and-play microelectronic ionic sensor, and the whole package is connected through the audio jack on the smartphone. It is used to measure nitrate concentration in water portably. The other method is called impedance sensing measurement. A portable device is used as the platform to combine with the impedance-based sensing technologies. It is designed to detect some species of Escherichia coli and Salmonella bacteria. The work discusses the system-level circuit design for the prototypes of both methods. The testing results from these two sensing methods have been confirmed with other existing analytical testing methods.Submission published under a 24 month embargo labeled 'U of I Access', the embargo will last until 2018-12-01The student, Han Zhang, accepted the attached license on 2016-09-14 at 15:13.The student, Han Zhang, submitted this Thesis for approval on 2016-09-14 at 15:33.This Thesis was approved for publication on 2016-09-16 at 13:09.DSpace SAF Submission Ingestion Package generated from Vireo submission #10157 on 2017-02-28 at 14:35:57Made available in DSpace on 2017-03-01T16:36:39Z (GMT). No. of bitstreams: 2
ZHANG-THESIS-2016.pdf: 991590 bytes, checksum: 11235aa6c54472ec71e0d69b70ff8ec7 (MD5)
LICENSE.txt: 4206 bytes, checksum: 0e054176f6ab990c50f8ad8030f4fbca (MD5)
Previous issue date: 2016-09-16Embargo set by: Seth Robbins for item 98569
Lift date: 2019-03-01T16:37:19Z
Reason: Author requested U of Illinois access only (OA after 2yrs) in Vireo ETD systemU of I Only Restriction Lifted for Item 98569 on 2019-03-02T10:15:14Z
Mobosens: Mobile software platform for concentration measurements on a smartphone
Full text linkThe development of mobile computing in recent decade enables various innovative applications on smartphones. Mobile applications have advantages over laboratory solutions for quantitative measurements of chemical concentrations in water. First, the cost of a mobile device is more affordable than professional measuring equipment; second, a mobile device is very portable and convenient for performing measuring tasks at multiple locations. In addition, easy access to mobile geographical data on a smartphone potentially extends data extraction and aggregation of measurements to a global level.
We describe MoboSens, a mobile software platform which aims at low-cost and portable concentration measurements for critical chemicals in both drinking water and the human circulatory system. The complete system of MoboSens contains a sensor circuit package and a smartphone application. Specifically, my efforts in this thesis focus on implementing the software interface designed for the circuit package and the cloud data engine for further data processing.Item withdrawn by Laura Spradlin ([email protected]) on 2014-04-28T18:51:18Z
Item was in collections:
University of Illinois Theses & Dissertations (ID: 1)
No. of bitstreams: 2
GraduateThesis2014_JunleQian.docx: 3011150 bytes, checksum: 2baae93bd1a0263466b5453a467a83ac (MD5)
Qian_Junle.pdf: 1388038 bytes, checksum: 249615226da2454a242d7a2f48ccbab0 (MD5)Made available in DSpace on 2014-05-30T17:07:38Z (GMT). No. of bitstreams: 3
Junle_Qian.pdf: 1382932 bytes, checksum: a62be126862caca141d4a610a8e78f2e (MD5)
GraduateThesis2014_JunleQian_v5.docx: 3010579 bytes, checksum: 7dd524274ad6754f3c3df17d7296de1b (MD5)
license.txt: 4058 bytes, checksum: 52cde93d7ca9205c1015a0c28333afb2 (MD5)Restriction data tranferred 2014-07-01T11:39:29-05:00
Original Data
Group with Access UIUC Users [automated]
Release Date: 2016-05-30 12:09:03 UTC
Reason: Author requested U of Illinois access only (OA after 2yrs) in Vireo ETD systemItem marked as restricted to the 'UIUC Users [automated]' Group (id=2) by Seth Robbins ([email protected]) on 2014-05-30T17:09:58Z
Item is restricted until 2016-05-30T17:09:03ZU of I Only Restriction Lifted for Item 49797 on 2016-09-22T20:59:16Z
Silicon nanopore patch clamp device for measuring single ion channel activity
Full text linkThe development of new methods for measuring and manipulating neural activity is of high interest with applications in neuron and neural circuit functioning as well as high-throughput ion channel screening for early drug development research. In 1991 Erwin Neher and Bert Sakmann received the Nobel Prize for their invention of the patch clamp, which is based on the formation of a high resistance seal between a glass micropipette and a cell membrane. This transformative method allows low noise recording of current arising from single ion channels or from an entire cell and has no equivalent in experimental neuroscience. However, the consistent formation and maintenance of a high resistance seal is nontrivial and unpredictable, requiring a large amount of time and labor, which is inconvenient and limits applications. In order to automate the patch clamp process, researchers have developed patch clamp on chip devices that are optimized for whole cell recordings. Here we have developed a novel silicon nanopore planar patch clamp chip that is ideal for single ion channel measurements because the nanopore apertures minimize cell membrane capacitance, reduce chip capacitance, reduce cell membrane damage, and allow for work with smaller cells. Here we give an overview of nanopore and nanoporous biodevices, the traditional patch clamp technqiue, requirements for noise reduction in patch clamp experiments, and recent advances in automated patch clamp. We then discuss our silicon nanopore fabrication method, which is based on wafer-scale anisotropic wet etching methods, and describe how this is incorporated into our patch clamp on chip device. We carry out electrical characterization of our devices before use to ensure that the impedance fulfills the requirements currently in place for single channel patch clamp recordings. In addition to device fabrication and characterization, we also present the single channel recordings we have obtained from the human neuron-like SH-SY5Y cell line cultured and differentiated on-chip.Item withdrawn by Laura Spradlin ([email protected]) on 2014-12-09T14:11:55Z
Item was in collections:
University of Illinois Theses & Dissertations (ID: 1)
No. of bitstreams: 1
Plucinski_Lisa.pdf: 3062887 bytes, checksum: a28e14b75e553a26581b8877c89e21c2 (MD5)Made available in DSpace on 2015-01-21T19:59:27Z (GMT). No. of bitstreams: 1
Lisa_Plucinski.pdf: 3062898 bytes, checksum: d05f56e3524549e30af5ffa61f154dd4 (MD5)Embargo set by: Seth Robbins for item 73281
Lift date: 2017-01-21T19:59:39Z
Reason: Author requested closed access (OA after 2yrs) in Vireo ETD systemLimited Restriction Lifted for Item 73281 on 2017-01-22T10:15:25Z
In vitro and in vivo imaging of peptide-encapsulated polymer nanoparticles for cancer biomarker activated drug delivery
Full text linkCancer creates one of the most significant public health problems not just in the United States, but worldwide. While one of the most effective treatment protocols for cancer is chemotherapy, the conventional agents used in chemotherapy affect normal tissue as well as cancerous tissue. This thesis reports the development of a new cancer drug delivery system based on nanoparticles, which is designed to target tumor sites better than previous practices.
In this study, nanoparticles coated with cathepsin D-specific peptides were developed as a vehicle for the targeted delivery of the cancer drug doxorubicin (DOX) to treat breast malignancy. Cathepsin D, a breast cancer cell secretion, triggers the release of DOX by digesting the protective peptide-coating layer of nanoparticles. Ultrasound imaging successfully detected fabricated nanoparticles in both in vitro conditions and in vivo mouse cancer models. Cell viability experiments were conducted to determine the efficacy of biomarker activation specific to breast cancer cell lines. These experimental results were compared with the outcome of a viability experiment run on non-cancerous cells. Viability decreased in human breast MCF7 cancer and mouse breast 4T1 cancer cells with no effect on fibroblast 3T3 non-cancerous cells. The next step was to obtain a real-time video of nanoparticle flow in mouse models using in-vivo ultrasound imaging. In vivo fluorescence imaging enabled the examination of cancerous mice injected with the drug-carrying nanoparticles. Results showed the distribution of nanoparticles in subject mice bodies, with concentrations in bladder and tumor sites. This finding suggests that nanoparticles are able to specifically target tumor tissues. It also suggests nanoparticles are resistant to nonspecific disintegration of peptide coating and consequential system drug release. Thus, the results of this work can be of great value for the development of more effective cancer treatment methods. Item withdrawn by Mark Zulauf ([email protected]) on 2012-04-25T16:15:14Z
Item was in collections:
University of Illinois Theses & Dissertations (ID: 1)
No. of bitstreams: 2
Thesis_MS.docx: 4490050 bytes, checksum: 5dbad85a66665824e0fcecae2266edfe (MD5)
Kulsharova_Gulsim.pdf: 5250851 bytes, checksum: 305d953cc3f671992de4efcbe00f08fe (MD5)Made available in DSpace on 2012-05-22T00:23:55Z (GMT). No. of bitstreams: 4
Kulsharova_Gulsim.pdf: 5321823 bytes, checksum: 8b08bbe981841cdc635d1046e1222565 (MD5)
Thesis_MS.docx: 4494179 bytes, checksum: a7dcc816cf35efebf59077c86de1ecbd (MD5)
1_Thesis_MS.docx: 4494179 bytes, checksum: a7dcc816cf35efebf59077c86de1ecbd (MD5)
license.txt: 4067 bytes, checksum: 3b3b13f787673492ae44d0a41289e3fc (MD5)Embargo placed at request of the author.
Restriction applied by [email protected] of I Only Restriction Lifted for Item 31314 on 2017-05-04T09:15:19Z
Microfluidic device for cytotoxicity screening
No full textCytotoxicity screening is important for the identification of different toxins and the quantification of toxin concentrations that can be detrimental to the proliferation of mammalian cells. Current cytotoxicity screening method requires initial cell seeding in 96-well cell culture plates and a large volume of culturing media, overall a time-consuming and resource-intensive process. We have developed a microfluidic device with internal structures that can evenly distribute cells across five chambers and requires only microliter volume of cell culturing media. In this study, we performed fluid dynamic simulations of different microfluidic designs with internal structures that can enhance the uniformity of distribution of cells in the initial seeding. We fabricated microfluidic devices with the optimal internal structures and performed several cell seeding experiments that showed high uniformity distribution of cells across all chambers. We have also performed cytotoxicity-screening experiments, using dimethyl sulfoxide and ethanol as toxins, to compare the performance between the microfluidic device and 96-well plate and the results showed close agreement between the two systems. Due to the generalizable design, this microfluidic device can be utilized in in vitro studies such as the response of cells to water-soluble factors such as anti-cancer drugs as well as the dynamic binding of anti-bodies to adherent cells.Item withdrawn by Alexis Thompson ([email protected]) on 2011-04-22T15:18:13Z
Item was in collections:
University of Illinois Theses & Dissertations (ID: 1)
No. of bitstreams: 2
Hsiao_YinKyai.doc: 11514880 bytes, checksum: 5d26af0785092f406e055a6bbf12170e (MD5)
Hsiao_YinKyai.pdf: 2113131 bytes, checksum: 9a88200a8eb746f36ff86148708b229a (MD5)Made available in DSpace on 2011-05-25T14:54:07Z (GMT). No. of bitstreams: 3
Hsiao_YinKyai.pdf: 2113131 bytes, checksum: 9a88200a8eb746f36ff86148708b229a (MD5)
license.txt: 4058 bytes, checksum: e6cd46b1133170a3912f9d53f5949c84 (MD5)
Hsiao_YinKyai.doc: 11514880 bytes, checksum: 5d26af0785092f406e055a6bbf12170e (MD5
Silicon-based pH sensor for biological and environmental applications
Full text linkIn biological and environmental applications, it is desirable to be able to measure hydrogen and hydroxyl ion concentrations (pH levels). Conventionally, the measurement processes take a considerable amount of time involving several calibration steps and handling of fragile electrodes. Here we propose a new, more robust and theoretically reliable way of sensing pH. Following a similar approach to Dr. Qingjun Liu’s work on the light-addressable potentiometric sensor (LAPS) from the Zhejiang University in China, we fabricated a silicon pH sensor, with polydimethylsiloxane (PDMS) fluidic channels for solution delivery and testing. Particularly for biological and environmental applications, the range of pH sensing is confined to 6 to 8.
The fabricated device used n-type silicon, so only five acidic solutions between pH 5 and pH 7 were tested. Device test results proved to be somewhat problematic. We were not able to obtain consistent capacitance measurements for a particular pH solution. For some solutions we had extremely large variances in capacitance, yielding “noisy” measurements. However, in retrospect, there are many improvements that could be made to our device and testing procedure in order to obtain more consistent capacitance readings, closer to the theoretical performance. Such changes include modifying the geometry of the electrode which supplies an AC signal for capacitance measurements, and ensuring airtight (PDMS) bonding with the device substrate, guaranteeing seamless solution delivery to the test chamber. It is our hope that future students are able to build upon these results and create a better, more reliable device.Item withdrawn by Katherine Eriksen ([email protected]) on 2012-07-10T15:47:56Z
Item was in collections:
University of Illinois Theses & Dissertations (ID: 1)
No. of bitstreams: 2
Gorti_Tejaswi.docx: 4626941 bytes, checksum: a1f17b40bc62b0399f042455e3867ba9 (MD5)
Gorti_Tejaswi.pdf: 1882375 bytes, checksum: 2bd4c9199cdbcbca002f7be0e1f92e4c (MD5)Made available in DSpace on 2012-09-18T21:07:52Z (GMT). No. of bitstreams: 3
Gorti_Tejaswi.pdf: 1882375 bytes, checksum: 2bd4c9199cdbcbca002f7be0e1f92e4c (MD5)
license.txt: 4061 bytes, checksum: c0b1ee9cd5799a197741a251445b57e1 (MD5)
Gorti_Tejaswi.docx: 4626941 bytes, checksum: a1f17b40bc62b0399f042455e3867ba9 (MD5
PC Sound Card-Based Oscilloscope
No full textA digital oscilloscope is the most commonly used device to observe and analyze an electrical signal. The device enables users not only to see the exact waveform of a desired signal, but also to easily obtain its wave properties such as amplitude, period, and wavelength. However, in some cases, a digital oscilloscope may not be available for use due to its size and high price.
The purpose of this project is to overcome the problem by developing a program in MATLAB for observation and analysis of an electrical signal with only a PC. This can be accomplished by using the soundcard of a PC as an analog-to-digital converter to acquire an analog input signal. Then, using the data acquisition method of the MATLAB software, the converted signal will be made available for observation and analysis.not peer reviewedSubmitted by Janice Progen ([email protected]) on 2014-01-17T16:02:39Z
No. of bitstreams: 1
ECE499-Su2011lee.pdf: 545338 bytes, checksum: aeaeb0d96bbc18f54982ceb9fc257b64 (MD5)Approved for entry into archive by James Hutchinson([email protected]) on 2014-01-17T18:52:56Z (GMT) No. of bitstreams: 1
ECE499-Su2011lee.pdf: 545338 bytes, checksum: aeaeb0d96bbc18f54982ceb9fc257b64 (MD5)Made available in DSpace on 2014-01-17T18:52:56Z (GMT). No. of bitstreams: 1
ECE499-Su2011lee.pdf: 545338 bytes, checksum: aeaeb0d96bbc18f54982ceb9fc257b64 (MD5)
Previous issue date: 2011-08Restriction data tranferred 2014-07-01T11:33:49-05:00
Original Data
Group with Access UIUC Users [automated]
Release Date: none
Reason: Undergraduate senior thesis not recommended for open accessItem marked as restricted to the 'UIUC Users [automated]' Group (id=2) by James Hutchinson ([email protected]) on 2014-01-17T18:52:56Z
Item is restricted indefinitely.Undergraduate senior thesis not recommended for open accessunpublishedU of I Onl
- …
