MRI: Acquisition of a Holographic Laser Tweezer Array for Submicron Control of Soft Materials and Novel Network Dynamics

这笔赠款支持购买全息激光镊子阵列。该仪器支持范围广泛的跨学科研究项目，包括非线性动力学、软凝聚态物理、物理化学和生物物理学。全息激光镊子阵列允许制造复杂材料，并使用通过显微镜物镜聚焦的多达200个独立可移动的激光光束来研究动态过程。该仪器允许产生复杂形状的力场，并同时操作多个被困物体。该系统可以产生光学涡旋，可以捕获反射粒子并向被捕获的物体施加扭矩。基于这些独特的性质，研究人员计划开展以下研究活动：(1)？？复杂形状的物体，如巨大的囊泡和细胞，将被低功率激光光斑的环捕获，这些光斑通过强度梯度提供相同的捕获功率，但峰值强度低于单个激光光斑，因此对样品的损害较小。它将允许通过变形激光光斑环将细胞和囊泡拉伸成任意形状，以研究膜弹性，以帮助理解自发细胞变形，如在神经生长和癌细胞扩散期间观察到的变形。将利用激光镊子阵列产生的复杂的力场或扭矩场来研究不断增长的生物聚合物网络所施加的力的分布及其对外力或应变的响应。结合上述环形陷阱，这将有助于研究细胞或细菌之间的粘附力或排斥力。一个特殊的应用将是生物膜的研究，这种生物膜经常感染医疗植入物。(3)？激光镊子阵列将允许创建由耦合光学振荡器组成的小世界网络的实验版本，以帮助了解稀疏连接网络中的同步和一致性条件。这种新型的分布式激光光源在医疗诊断和微波探测方面具有潜在的应用前景。在物理、化学和生物之间建立一个实验研究设施，将促进教师、博士后和研究生之间的跨学科互动。此外，该工具将通过私人投资机构持续参与外联工作对K-12教育产生影响，例如为DC地区高中代表不足的群体进行实验室参观和暑期实习。对于该大学来说，该仪器将增强研究基础设施，这将增加一项新的努力，将生物物理学研究扩展并连接到一个可见的、高质量的研究和教育项目中。凭借其独特的能力，该系统也将对区域研究界有用。PIS与NIH和NIST的研究人员开发了联合项目，这些项目利用了NIH在生物科学和NIST材料研究方面的巨大区域优势。

This grant supports the acquisition of a holographic laser tweezer array. The instrument supports a broad range of cross-disciplinary research projects in nonlinear dynamics, soft condensed matter physics, physical chemistry, and biophysics. The holographic laser tweezer array permits the fabrication of complex materials and the study of dynamical processes using up to 200 independently moveable laser light beams focused through a microscope objective. The instrument permits the generation of complex shaped force fields, and the simultaneous manipulation of multiple trapped objects. The system can generate optical vortices, which can trap reflective particles and apply torque to trapped objects. Based on these unique properties, the investigators plan the following research activities: (1) ??Complex shaped objects such as giant vesicles and cells will be trapped with rings of low power laser spots, which provide the same trapping power through intensity gradient, but have less peak intensity than a single laser spot, and are thus less damaging to the sample. It will permit stretching cells and vesicles into arbitrary shapes by deforming the ring of laser spots for studies of membrane elasticity to aid in understanding spontaneous cell deformations, such as those observed during nerve growth and during the spread of cancerous cells. ?(2) ??Complex force or torque fields generated by the laser tweezer array will be utilized to study the distribution of forces exerted by growing biopolymer networks and their response to external forces or strains. In conjunction with the ring traps described above this will permit studies of sticking or repulsive forces between cells or bacteria. One particular application will be the study of biofilms, which often infect medical implants. (3) ?Arrays of laser tweezers will allow creation of experimental versions of small-world networks, composed of coupled optical oscillators, in order to help understand conditions for synchronization and coherence in sparsely connected networks. Such novel distributed laser sources have potential applications in medical diagnostics and microwave detection. The establishment of an experimental research facility at the interface between physics, chemistry and biology will foster cross-disciplinary interactions among faculty, post- docs and graduate students. Additionally, the instrument will have impact on K-12 education through the PIs ongoing participation in outreach efforts, such as laboratory tours and summer internships for underrepresented groups from DC area high schools. For the University, the instrument will enhance the research infrastructure, which will add to a new effort to expand and connect biophysics research into a visible, top quality research and education program. With its unique capabilities, the system will also be useful for the regional research community. The PIs have developed joint projects with researchers at NIH and NIST, which take advantage of the great regional strengths in the biosciences at NIH, and in materials research at NIST.