Microfluidic sorting of mammalian cells by optical force switching.

Microfluidic-based devices have allowed miniaturization and increased parallelism of many common functions in biological assays; however, development of a practical technology for microfluidic-based fluorescence-activated cell sorting has proved challenging. Although a variety of different physical on-chip switch mechanisms have been proposed, none has satisfied simultaneously the requirements of high throughput, purity, and recovery of live, unstressed mammalian cells. Here we show that optical forces can be used for the rapid (2-4 ms), active control of cell routing on a microfluidic chip.

Time-of-flight optophoresis analysis of live whole cells in microfluidic channels.

Optophoresis is a non-invasive cell analysis technique that is based on the interaction of live whole cells with optical gradient fields, typically generated by a near-infrared laser. The magnitude of the interaction depends upon the intrinsic physical properties of the cells, such as their refractive index, composition, size, and morphology. Time-of-flight (TOF) optophoresis is an implementation of this technique in a microfluidic environment.

Use of moving optical gradient fields for analysis of apoptotic cellular responses in a chronic myeloid leukemia cell model.

To facilitate quantitation of cellular apoptotic responses to various antineoplastic agents, a laser-based technology, Optophoresis, has been developed to provide analysis of cells without any need for labeling or cell processing. Optophoresis is defined as the analysis of the motion of cells, where the motion is either induced or modified by a moving optical gradient field, which produces radiation pressure forces on the cells in an aqueous suspension. Quantitation of the induced motion provides a basis for distinguishing one population of cells from another.

Optical forces for noninvasive cellular analysis.

A novel, noninvasive measurement technique for quantitative cellular analysis is presented that utilizes the forces generated by an optical beam to evaluate the physical properties of live cells in suspension. In this analysis, a focused, near-infrared laser line with a high cross-sectional intensity gradient is rapidly scanned across a field of cells, and the interaction of those cells with the beam is monitored. The response of each cell to the laser depends on its size, structure, morphology, composition, and surface membrane properties; therefore, with this technique, cell populations of different type, treatment, or biological state can be compared.

Misalignment tolerance analysis of free-space optical interconnects via statistical methods.

System-level packaging is one of the critical issues that need to be addressed for free space optical interconnections (FSOI) to become useful in desktop systems. The performance of FSOI, e.g.

Three-dimensional optoelectronic stacked processor by use of free-space optical interconnection and three-dimensional VLSI chip stacks.

We present a demonstration system under the three-dimensional (3D) optoelectronic stacked processor consortium. The processor combines the advantages of optics in global, high-density, high-speed parallel interconnections with the density and computational power of 3D chip stacks. In particular, a compact and scalable optoelectronic switching system with a high bandwidth is designed.