A. James Clark School of Engineering
Permanent URI for this communityhttp://hdl.handle.net/1903/1654
The collections in this community comprise faculty research works, as well as graduate theses and dissertations.
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Item Chitosan to Connect Biology to Electronics: Fabricating the Bio-Device Interface and Communicating Across This Interface(MDPI, 2014-12-24) Kim, Eunkyoung; Xiong, Yuan; Cheng, Yi; Wu, Hsuan-Chen; Liu, Yi; Morrow, Brian H.; Ben-Yoav, Hadar; Ghodssi, Reza; Rubloff, Gary W.; Shen, Jana; Bentley, William E.; Shi, Xiaowen; Payne, Gregory F.Individually, advances in microelectronics and biology transformed the way we live our lives. However, there remain few examples in which biology and electronics have been interfaced to create synergistic capabilities. We believe there are two major challenges to the integration of biological components into microelectronic systems: (i) assembly of the biological components at an electrode address, and (ii) communication between the assembled biological components and the underlying electrode. Chitosan possesses a unique combination of properties to meet these challenges and serve as an effective bio-device interface material. For assembly, chitosan’s pH-responsive film-forming properties allow it to “recognize” electrode-imposed signals and respond by self-assembling as a stable hydrogel film through a cathodic electrodeposition mechanism. A separate anodic electrodeposition mechanism was recently reported and this also allows chitosan hydrogel films to be assembled at an electrode address. Protein-based biofunctionality can be conferred to electrodeposited films through a variety of physical, chemical and biological methods. For communication, we are investigating redox-active catechol-modified chitosan films as an interface to bridge redox-based communication between biology and an electrode. Despite significant progress over the last decade, many questions still remain which warrants even deeper study of chitosan’s structure, properties, and functions.Item Catechol-Based Hydrogel for Chemical Information Processing(MDPI, 2017-07-03) Kim, Eunkyoung; Liu, Zhengchun; Liu, Yi; Bentley, William E.; Payne, Gregory F.Catechols offer diverse properties and are used in biology to perform various functions that range from adhesion (e.g., mussel proteins) to neurotransmission (e.g., dopamine), and mimicking the capabilities of biological catechols have yielded important new materials (e.g., polydopamine). It is well known that catechols are also redox-active and we have observed that biomimetic catechol-modified chitosan films are redox-active and possess interesting molecular electronic properties. In particular, these films can accept, store and donate electrons, and thus offer redox-capacitor capabilities. We are enlisting these capabilities to bridge communication between biology and electronics. Specifically, we are investigating an interactive redox-probing approach to access redox-based chemical information and convert this information into an electrical modality that facilitates analysis by methods from signal processing. In this review, we describe the broad vision and then cite recent examples in which the catechol–chitosan redox-capacitor can assist in accessing and understanding chemical information. Further, this redox-capacitor can be coupled with synthetic biology to enhance the power of chemical information processing. Potentially, the progress with this biomimetic catechol–chitosan film may even help in understanding how biology uses the redox properties of catechols for redox signaling.Item Techniques and Applications of Mesoscopic Fluorescence Imaging(2019) Liu, Yi; Chen, Yu; Bioengineering; Digital Repository at the University of Maryland; University of Maryland (College Park, Md.)There is increasing interest towards visualization of tissue level with deep penetration depth in bioscience and medical research, mesoscopic imaging exchanges resolution for penetration depth, which offers hundreds of micrometer resolution and up to several millimeter penetration depth. By introducing fluorescence dyes or with intrinsic fluorescence, much higher contrast of images can be recorded compared to reflection imaging. To assess the characteristics of fluorescence imaging system, in the first part of this thesis I will discuss 3D printing technique as a novel phantom fabrication method which enables the fabrication of optically realistic and morphologically complex tissue-simulating phantoms for the development and evaluation of optical imaging products. In the second part, I will discuss about the techniques and applications of Angled fluorescence laminar optical tomography (aFLOT), a modified fluorescence tomographic imaging technique based on 3D reconstructions. To extend the capability of aFLOT to acquire more bioinformation besides, its availability for quantification and statistics has been studied. Some technical improvements of aFLOT system performance has also been taken by incorporating algorithms for imaging processing. In addition, examples of biomedical applications have been discussed to demonstrate the capability of aFLOT system in both bioscience and medical research field.