Collaborative Research: IDBR: Metamaterial Enhanced Spectrometer for Terahertz Hyperspectral Imaging of Biological Specimens

合作研究：IDBR：用于生物样本太赫兹高光谱成像的超材料增强光谱仪

• 批准号: 1063222
• 负责人: Willie Padilla
• 金额: $ 17.5万
• 依托单位: Boston College
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2011
• 资助国家: 美国
• 起止时间: 2011-05-01 至 2013-04-30
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1063222&HistoricalAwards=false
• 关键词: Collaborative; Research; IDBR; Metamaterial; Enhanced

Project SummaryCollaborative Research: IDBR: Metamaterial Enhanced Spectrometer for Hyperspectral Terahertz Imaging of Biological Specimens The objective of the proposed research is the development of novel instrumentation to facilitate highly sensitive, hyperspectral imaging of biological specimens, in the minimally explored yet information-rich electromagnetic spectrum of terahertz frequencies. This spectrum is broad in spectroscopic possibilities due to presence of the intermolecular vibrational, rotational and torsional modes, providing a distinct broadband molecular fingerprint and intrinsic contrast for biomolecular identification. However existing terahertz imaging approaches have limited sensitivity due to (1) Lack of efficient coupling of terahertz radiation in and out of the biological sample, (2) Higher level of signal loss due to unwanted scattering at sample/spectrometer interface, and (3) Lack of efficient detectors in the terahertz frequency range, thus limiting their performance. Moreover the detectors are typically single pixel detectors that require scanning to obtain a 2D image and they fail to capture the spatiotemporal evolution of biomolecular dynamics.To solve these issues, the proposed instrument brings two emergent technologies ¨C (1) Metamaterials (MMs) and (2) Plasma wave operation of GaAs pHEMT device. Metamaterials are artificial structures with subwavelength metallic inclusions that can be designed to exhibit exotic electromagnetic response such as negative permittivity and permeability, negative index, and ideal absorption or transmittance. Plasma wave operation of GaAs pHEMT device facilitates resonant detection of terahertz radiation with unparalleled sensitivity. Intellectual Merit: The proposed program will result in the development of a Metamaterial Enhanced Reflectance (or Transmittance) Imaging Terahertz (MERIT/METIT) spectrometer as an ultrasensitive platform for terahertz imaging of cells and tissues. These spectrometers will shed new light on ultra-fast conformational protein dynamics (protein folding) and other biomolecular processes responsible for pathogenesis in many human diseases, primarily cancer. Key technical innovations of the proposed spectrometer are (1) Realization of perfect impedance matched spectral conjugate layers to eliminate spurious reflections and to mitigate effects of water absorption, and (2) Realization of a high speed (106 frames/sec), large 2D terahertz focal plane array (TFPA) based on resonant plasma wave detection of terahertz radiation by a GaAs pHEMT device. An interdisciplinary collaboration between PIs at multiple institutions (Boston College and Tufts University) with records of achievement in metamaterials theory, simulation and experiment, HEMT transistor device modeling and fabrication, and practical knowledge in imaging, evince the potential for carrying out a successful research and educational program. Broader Impact: Beyond providing rich spectroscopic images of biological cells and tissues for fundamental studies, the instrument has potential in medical diagnostics and drug discovery. The PIs plan to reach out to the biology community through articles in print and online magazines frequented by biologists. The instrument will be made accessible to Boston area researchers for evaluation purposes. The instrument development project will establish a research and teaching laboratory at Boston College and Tufts University in the area of metamaterials and THz imaging devices. It will train the future generation of science and engineering majors in experimental techniques, such as extremely broadband frequency domain spectroscopy, fabrication of metamaterials, GaAs III-V technology as well as computer simulation techniques. The PIs have a strong commitment to undergraduate research through involvement in (1) summer scholars and BEND program for undergraduate research, and (2) the McNair scholarship program, a graduate school preparation program for students from underrepresented groups. Activities aimed at K©\12 outreach is made possible through the ongoing Student Teacher Outreach Mentor Program (STOMP). The PIs plan to share the excitement of their research and discovery through lectures at local high©\schools and development of web-based tutorials.

项目概要合作研究：IDBR：超材料增强型光谱仪用于生物标本的超光谱太赫兹成像拟议研究的目的是开发新型仪器，以促进生物标本的高灵敏度，超光谱成像，在最低限度探索但信息丰富的太赫兹频率的电磁频谱。由于存在分子间振动、旋转和扭转模式，该光谱在光谱学可能性方面是宽的，从而为生物分子鉴定提供了独特的宽带分子指纹和内在对比度。然而，现有的太赫兹成像方法由于以下原因而具有有限的灵敏度：（1）缺乏太赫兹辐射进出生物样本的有效耦合，（2）由于样本/光谱仪界面处的不期望的散射而导致的较高水平的信号损失，以及（3）缺乏太赫兹频率范围内的有效检测器，从而限制了它们的性能。为了解决这些问题，提出了两种新兴的技术：（1）超材料（Metamaterials，简称MEMT）技术和（2）GaAs pHEMT器件的等离子体波操作技术。超材料是具有亚波长金属夹杂物的人造结构，其可以被设计为表现出奇异的电磁响应，例如负介电常数和负磁导率、负折射率以及理想的吸收或透射。GaAs pHEMT器件的等离子体波操作有利于以无与伦比的灵敏度共振检测太赫兹辐射。智力优势：拟议的计划将导致超材料增强反射（或透射）成像太赫兹（MERIT/METIT）光谱仪的开发，作为细胞和组织太赫兹成像的超灵敏平台。这些光谱仪将为超快速构象蛋白质动力学（蛋白质折叠）和其他生物分子过程提供新的视角，这些生物分子过程负责许多人类疾病（主要是癌症）的发病机制。提出的光谱仪的关键技术创新是（1）实现完美的阻抗匹配的光谱共轭层，以消除寄生反射和减轻水吸收的影响，和（2）实现高速（106帧/秒），大的2D太赫兹焦平面阵列（TFPA）的基础上的太赫兹辐射的GaAs pHEMT器件的共振等离子体波检测。多个机构（波士顿学院和塔夫茨大学）的PI之间的跨学科合作，在超材料理论，模拟和实验，HEMT晶体管器件建模和制造以及成像实践知识方面取得了成就，表明了成功开展研究和教育计划的潜力。更广泛的影响：除了为基础研究提供丰富的生物细胞和组织光谱图像外，该仪器还具有医学诊断和药物发现的潜力。PI计划通过生物学家经常光顾的印刷和在线杂志上的文章接触生物学界。该仪器将提供给波士顿地区的研究人员进行评估。仪器开发项目将在波士顿学院和塔夫茨大学建立一个超材料和太赫兹成像设备领域的研究和教学实验室。它将培养未来一代的科学和工程专业的实验技术，如极宽带频域光谱学，超材料的制造，GaAs III-V技术以及计算机模拟技术。PI通过参与（1）夏季学者和本科研究弯曲计划，以及（2）McNair奖学金计划，为代表性不足的群体的学生提供研究生院准备计划，对本科研究做出了坚定的承诺。通过正在进行的学生教师外联导师计划（STOMP），旨在K©\12外联的活动成为可能。PI计划通过在当地高中的讲座和基于网络的教程的开发来分享他们的研究和发现的兴奋。