Carl F. Edman

Anchored multiplex amplification on a microelectronic chip array

We have developed a method for anchored amplification on a microchip array that allows amplification and detection of multiple targets in an open format. Electronic anchoring of sets of amplification primers in distinct areas on the microchip permitted primer-primer interactions to be reduced and distinct zones of amplification created, thereby increasing the efficiency of the multiplex amplification reactions. We found strand displacement amplification (SDA) to be ideal for use in our microelectronic chip system because of the isothermal nature of the assay, which provides a rapid amplification system readily compatible with simple instrumentation. Anchored SDA supported multiplex DNA or RNA amplification without decreases in amplification efficiency. This microelectronic chip-based amplification system allows multiplexed amplification and detection to be performed on the same platform, streamlining development of any nucleic acid-based assay.

Electric field directed assembly of an InGaAs LED onto silicon circuitry

We demonstrate an electrophoretic process for assembling very small devices on a silicon circuit. A 20-/spl mu/m diameter InGaAs LED was fabricated and then released from the substrate by etching a sacrificial layer underneath the diode structure. The diode, placed into a buffer solution over the silicon circuit, was positioned onto the circuits tin/lead contact electrodes by biasing the contacts to establish an electrophoretic current in the buffer solution. Following removal from the buffer solution, the assembly was heated to reflow the solder. Circuit formation and LED activation is demonstrated by forward biasing the LED using the silicon circuits contacts.

DNA technology for optoelectronics

High performance photonics systems and subsystems require increasing sophistication in packaging and assembly technology to achieve their performance targets. We are exploring DNA labelling techniques to achieve the precise placement of semiconductor structures on host substrates. These labelling techniques allow the electrophoretic transport of the semiconductor structures in solution, as well as the specific matching of structures to host locations due to the complementary base pairing inherent in DNA hybridization. By configuring an electrode array on the host substrate, various semiconductor structures may be manipulated in solution using the electric fields created by applying a potential to the electrodes. In conjunction with the inherent selectivity of the DNA base pairing (in a process known as hybridization) specific placement and orientation of the structures on the host substrate may be achieved.

Directed assembly of optoelectronic components using electric fields

We have demonstrated the directed assembly of objects ranging in size from 100 nm to 10 /spl mu/m onto electrode arrays fabricated on Si substrates. An example of this technology is shown. This experiment involves the manipulation of plastic beads of various sizes in solution over the chip.

ELECTRIC FIELD ASSISTED SELF-ASSEMBLY OF DNA BASED MOLECULAR CHROMOPHORE COMPONENTS FOR OPTICAL DATA STORAGE AND OTHER NANOTECHNOLOGY APPLICATIONS

Active microelectronic DNA arrays are presently being used for genomic research and diagnostics. These arrays transport charged DNA molecules to specific microscopic sites. These devices can serve as