Optical magnetic twisting cytometry and traction force microscopy are two advanced cell mechanics research tools that employ optical methods to track the motion of microbeads that are either bound to the surface or em...Optical magnetic twisting cytometry and traction force microscopy are two advanced cell mechanics research tools that employ optical methods to track the motion of microbeads that are either bound to the surface or embedded in the substrate underneath the cell.The former measures rheological properties of the cell such as cell stiffness,and the latter measures cell traction force dynamics.Here we describe the principles of these two cell mechanics research tools and an example of using them to study physical behaviors of the living cell in response to transient stretch or compression.We demonstrate that,when subjected to a stretchunstretch manipulation,both the stiffness and traction force of adherent cells promptly reduced,and then gradually recover up to the level prior to the stretch.Immunofluorescent staining and Western blotting results indicate that the actin cytoskeleton of the cells underwent a corresponding disruption and reassembly process almost in step with the changes of cell mechanics.Interestingly,when subjected to compression,the cells did not show such particular behaviors.Taken together,we conclude that adherent cells are very sensitive to the transient stretch but not transient compression,and the stretch-induced cell response is due to the dynamics of actin polymerization.展开更多
In order to apply compressive sensing in wireless sensor network, inside the nodes cluster classified by the spatial correlation, we propose that a cluster head adopts free space optical communication with space divis...In order to apply compressive sensing in wireless sensor network, inside the nodes cluster classified by the spatial correlation, we propose that a cluster head adopts free space optical communication with space division multiple access, and a sensor node uses a modulating retro-reflector for communication. Thus while a random sampling matrix is used to guide the establishment of links between head cluster and sensor nodes, the random linear projection is accomplished. To establish multiple links at the same time, an optical space division multiple access antenna is designed. It works in fixed beams switching mode and consists of optic lens with a large field of view（FOV）, fiber array on the focal plane which is used to realize virtual channels segmentation, direction of arrival sensor, optical matrix switch and controller. Based on the angles of nodes＇ laser beams, by dynamically changing the route, optical matrix switch actualizes the multi-beam full duplex tracking receiving and transmission. Due to the structure of fiber array, there will be several fade zones both in the focal plane and in lens＇ FOV. In order to lower the impact of fade zones and harmonize multibeam, a fiber array adjustment is designed. By theoretical, simulated and experimental study, the antenna＇s qualitative feasibility is validated.展开更多
We present an optical/inertial data fusion system for motion tracking of the robot manipulator, which is proved to be more robust and accurate than a normal optical tracking system(OTS). By data fusion with an inertia...We present an optical/inertial data fusion system for motion tracking of the robot manipulator, which is proved to be more robust and accurate than a normal optical tracking system(OTS). By data fusion with an inertial measurement unit(IMU), both robustness and accuracy of OTS are improved. The Kalman filter is used in data fusion. The error distribution of OTS pro-vides an important reference on the estimation of measurement noise using the Kalman filter. With a proper setup of the system and an effective method of coordinate frame synchronization, the results of experiments show a significant improvement in terms of robustness and position accuracy.展开更多
To synchronize a control signal with a packet signal in response to changing timing jitter, we investigate ultra-short pulse tracking by using wavelength dispersion for a short-time optical buffer in an optical router.
We design a novel wireless laser power transmission system in which the process of wireless power transmission to a dynamic target was completed based on the rotation of just one component.The design of this system no...We design a novel wireless laser power transmission system in which the process of wireless power transmission to a dynamic target was completed based on the rotation of just one component.The design of this system not only reduces the loadbearing of the gimbal,but also avoids the degradation of beam quality caused by lens vibration when tracking dynamic targets.As a result,this WLPT system has been verified by tracking an unmanned aerial vehicle at 122 m away with an offset distance of±26.7 mm.We believe this system offers great potential in highpower,longdistance dynamic laser power transmission.展开更多
文摘Optical magnetic twisting cytometry and traction force microscopy are two advanced cell mechanics research tools that employ optical methods to track the motion of microbeads that are either bound to the surface or embedded in the substrate underneath the cell.The former measures rheological properties of the cell such as cell stiffness,and the latter measures cell traction force dynamics.Here we describe the principles of these two cell mechanics research tools and an example of using them to study physical behaviors of the living cell in response to transient stretch or compression.We demonstrate that,when subjected to a stretchunstretch manipulation,both the stiffness and traction force of adherent cells promptly reduced,and then gradually recover up to the level prior to the stretch.Immunofluorescent staining and Western blotting results indicate that the actin cytoskeleton of the cells underwent a corresponding disruption and reassembly process almost in step with the changes of cell mechanics.Interestingly,when subjected to compression,the cells did not show such particular behaviors.Taken together,we conclude that adherent cells are very sensitive to the transient stretch but not transient compression,and the stretch-induced cell response is due to the dynamics of actin polymerization.
基金supported by the National Natural Science Foundation of China(61372069)and the"111"Project(B08038)
文摘In order to apply compressive sensing in wireless sensor network, inside the nodes cluster classified by the spatial correlation, we propose that a cluster head adopts free space optical communication with space division multiple access, and a sensor node uses a modulating retro-reflector for communication. Thus while a random sampling matrix is used to guide the establishment of links between head cluster and sensor nodes, the random linear projection is accomplished. To establish multiple links at the same time, an optical space division multiple access antenna is designed. It works in fixed beams switching mode and consists of optic lens with a large field of view（FOV）, fiber array on the focal plane which is used to realize virtual channels segmentation, direction of arrival sensor, optical matrix switch and controller. Based on the angles of nodes＇ laser beams, by dynamically changing the route, optical matrix switch actualizes the multi-beam full duplex tracking receiving and transmission. Due to the structure of fiber array, there will be several fade zones both in the focal plane and in lens＇ FOV. In order to lower the impact of fade zones and harmonize multibeam, a fiber array adjustment is designed. By theoretical, simulated and experimental study, the antenna＇s qualitative feasibility is validated.
基金Project supported by the National Natural Science Foundation of China(No.51221004)Sponsored Research between ABB Re-search Ltd. and Zhejiang University
文摘We present an optical/inertial data fusion system for motion tracking of the robot manipulator, which is proved to be more robust and accurate than a normal optical tracking system(OTS). By data fusion with an inertial measurement unit(IMU), both robustness and accuracy of OTS are improved. The Kalman filter is used in data fusion. The error distribution of OTS pro-vides an important reference on the estimation of measurement noise using the Kalman filter. With a proper setup of the system and an effective method of coordinate frame synchronization, the results of experiments show a significant improvement in terms of robustness and position accuracy.
文摘To synchronize a control signal with a packet signal in response to changing timing jitter, we investigate ultra-short pulse tracking by using wavelength dispersion for a short-time optical buffer in an optical router.
文摘We design a novel wireless laser power transmission system in which the process of wireless power transmission to a dynamic target was completed based on the rotation of just one component.The design of this system not only reduces the loadbearing of the gimbal,but also avoids the degradation of beam quality caused by lens vibration when tracking dynamic targets.As a result,this WLPT system has been verified by tracking an unmanned aerial vehicle at 122 m away with an offset distance of±26.7 mm.We believe this system offers great potential in highpower,longdistance dynamic laser power transmission.
