Justin K. Valley

Learn More
We report on a new light-actuated digital microfluidics device which is capable of using on demand, &#x2018;virtual&#x2019; electrodes formed by a data projector to enable large-scale, parallel manipulation of arbitrarily sized droplets. The device features a thin, high-quality Al<inf>2</inf>O<inf>3</inf> film deposited via atomic layer deposition (ALD)(More)
The authors demonstrate an optical manipulation mechanism of gas bubbles for microfluidic applications. Air bubbles in a silicone oil medium are manipulated via thermocapillary forces generated by the absorption of a laser in an amorphous silicon thin film. In contrast to previous demonstrations of optically controlled thermally driven bubble movement,(More)
In this paper we present trap profile measurements for HeLa cells in Optoelectronic Tweezers (OET) based on a data projector. The data projector is used as a light source to illuminate amorphous Si creating virtual electrodes which are used to trap particles through dielectrophoresis. We show that although the trap stiffness is typically greater at the(More)
Electroporation is a common technique for the introduction of exogenous molecules across the, otherwise, impermeant cell membrane. Conventional techniques are limited by either low throughput or limited selectivity. Here we present a novel technique whereby we use patterned light to create virtual electrodes which can induce the parallel electroporation of(More)
We introduce NanoPen, a novel technique for low optical power intensity, flexible, real-time reconfigurable, and large-scale light-actuated patterning of single or multiple nanoparticles, such as metallic spherical nanocrystals, and one-dimensional nanostructures, such as carbon nanotubes. NanoPen is capable of dynamically patterning nanoparticles over an(More)
Selection of optimal quality embryos for in vitro fertilization (IVF) transfer is critical to successful live birth outcomes. Currently, embryos are chosen based on subjective assessment of morphologic developmental maturity. A non-invasive means to quantitatively measure an embryo's developmental maturity would reduce the variability introduced by the(More)
Here we report the use of optoelectronic tweezers and dynamic virtual electrodes to address multiwalled carbon nanotubes (MWCNTs) with trap stiffness values of approximately 50 fNmum. Both high-speed translation (>200 mums) of individual-MWCNTs and two-dimensional trapping of MWCNT ensembles are achieved using 100,000 times less optical power density than(More)
The high throughput electroporation of single cells is important in applications ranging from genetic transfection to pharmaceutical development. Light-induced electroporation using optoelectronic tweezers (OET) shows promise towards achieving this goal. However, cell viability following light-induced electroporation has yet to be shown. Here we present a(More)
We report on trapping of single and multiple spherical gold nanoparticles with 60 to 250 nm diameters using optoelectronic tweezers (OET). Thanks to the low optical intensities required for stable trapping (20 ¿W over 1.7 ¿m spot), we estimate the temperature increase in OET-trapped nanoparticles due to absorption to be ¿T &#x226A; 0.1°C, making OET-trapped(More)
Optoelectronic tweezers was used to manipulate human spermatozoa to determine whether their response to OET predicts sperm viability among non-motile sperm. We review the electro-physical basis for how live and dead human spermatozoa respond to OET. The maximal velocity that non-motile spermatozoa could be induced to move by attraction or repulsion to a(More)