We demonstrate a multi-functional optical trap capable of trapping, motion control, position sensing and fluorescence detection of chemically treated polystyrene beads, using off-the-shelve optical components. It consists of two collinearly aligned single-mode fibers separated by a spacing of 130-170mum for trapping, another single-mode fiber for probing/pumping and a fourth multi-mode fiber for optical detection. The fibers are mounted either on V-grooved Si or PDMS platforms fabricated using microfabrication and molding techniques, respectively. The result represents an important milestone towards a functional integrated trapping platform.

We introduce microcarriers referred to as ''micropallets'' ranging in size from 25 lm to several 100 microns, fabricated using photoresist or other polymer materials. These small carrier structures may be used in static detection systems or for transporting attached biological or chemical samples through a microfluidic system. Micropallets may be encoded through the use of barcodes or other markings and engineered to optimally suit the cargo they carry. We demonstrate the use of micropallets in cell and antibody assays. Furthermore we demonstrate the ability to decode and manipulate micropallets in a flow-through system.

We report on a novel system for the analysis of adherent cells. Using standard lithography techniques, cell pallets are fabricated upon which cells are cultured and subsequently transported through a microfluidic system. This technology eliminates the need for the release of a cell from its growth surface, which can lead to membrance damage, and/or disruption of normal cell functions. We have demonstrated RBL (rat basophil leukemia) cells will grow on SU8 pallets and remain viable after the pallet is released. Cells on pallets can then be sorted based on pre-selected criteria and sent to a docking station for cell assays. Once completed, the cells may be interrogated and retained for further processing or disposal.

Bead and cell suspension based flow-through assays are popular for high throughput biological analysis. Several technologies incorporate a tagging scheme with beads to enable multiplexing. Modern flow-through systems such as flow cytometers and cell sorters are large, bulky and expensive; consequently, much research has been performed using microfluidics to miniaturize these systems. However, several problems remain with these systems, notably it remains difficult to perform manipulations on the beads (or cells), and in the case of multiplexed systems, it remains difficult to read the tags quickly. In this paper, we present a micromachined micro-carrier, referred to as a ‘micropallet’, designed to move through a microfluidic device, which helps to solve several of these problems. Micropallets are small carrier structures, micromachined out of plastic or other materials, that are used to carry attached biological or chemical samples through a microfluidic system (e.g., DNA, RNA, proteins, antibodies, adherent cells, organisms). Similar to conventional factory pallets that carry a product through an automated manufacturing line, micropallets are engineered to carry their cargo through a micro-scale system. Thus micropallets may contain shapes, structures and materials designed to interact with and work in a microfluidic system, such as for docking, sorting, manipulation and readout. Additionally, micropallets may include bar codes or other markings, and be engineered to optimally suit the cargo they carry (for example, a micropallet might contain 3-D structures and treated sections for cells, molecules or organisms to attach). Results are presented for the use of micropallets in cell assays, DNA assays and antibody assays. Micropallets may be designed to carry a sample through a microfluidic system or for use in a static assay system, enabling versatile customisation of the micropallets and flow system for design of a programmable system that interacts with the micropallets for detection, control and manipulation.