Publications by Andreas Vasdekis

Optofluidics of plants

Demetri Psaltis, Jae-Woo Choi, Andreas Vasdekis

Optofluidics is a tool for synthesizing optical systems, making use of the interaction of light with fluids. In this paper we explore optofluidic mechanisms that have evolved in plants where sunlight and fluidic control combine to define most of the functi ...

2016

Cytoplasmic Stopped Flow at the Single Cell Level Based on Photosensitive Polymersomes

Jeffrey Alan Hubbell, Conlin O'Neil, Demetri Psaltis, Andreas Vasdekis

Cell Press2014

Vesicle Photonics

Jeffrey Alan Hubbell, Demetri Psaltis, Andreas Vasdekis, Sylvie Roke

Amphiphiles, under appropriate conditions, can self-assemble into nanoscale thin membrane vessels (vesicles) that encapsulate and hence protect and transportmolecular payloads.Vesicles assemble naturally within cells but can also be artificially synthesize ...

Annual Reviews2013

Optofluidic-tunable color filters and spectroscopy based on liquid-crystal microflows

Julien Cuennet, Demetri Psaltis, Andreas Vasdekis

The integration of color filters with microfluidics has attracted substantial attention in recent years, for on-chip absorption, fluorescence, or Raman analysis. We describe such tunable filters based on the micro-flow of liquid crystals. The filter operat ...

Royal Society of Chemistry2013

Optofluidic Microstructures Containing Liquid Crystals

Andreas Vasdekis, Luciano De Sio, Marilisa Romito

We report our recent efforts on the realization and characterization of a conductive polydimethylsiloxane (PDMS) microstructure containing liquid crystals (LC). The sample has been realized by means of a layer by layer strategy. An indium tin oxide (ITO) l ...

Taylor & Francis Ltd2013

Single microbe trap and release in sub-microfluidics

Andreas Vasdekis

Life on Earth is comprised mostly of microbes with significant implications in disease and carbon cycling. However, their dimensions and mobility make microbes challenging to analyse on-chip. A sub-micron resolution microfluidic system (sub-microfluidics) ...

Royal Soc Chemistry2013

Double-helix enhanced axial localization in STED nanoscopy

Demetri Psaltis, Andreas Vasdekis, Grégoire Pierre Jean Laporte, Donald Benjaman Conkey

Stimulated Emission Depletion (STED) microscopy enables subdiffraction resolution in the imaging plane. However, STED's lateral improvement in resolution is generally better than the enhancement in the axial direction. Here, we combine conventional STED su ...

Optical Society of America2013

Electro-switchable polydimethylsiloxane-based optofluidics

Andreas Vasdekis, Luciano De Sio, Marilisa Romito

We report on the fabrication and characterization of a new generation of electro-switchable optofluidic devices based on flexible substrates, combined with the extraordinary properties of reconfigurable soft-materials. A conductive polydimethylsiloxane mic ...

Royal Soc Chemistry2012

Precision Intracellular Delivery Based on Optofluidic Polymersome Rupture

Jeffrey Alan Hubbell, Conlin O'Neil, Demetri Psaltis, Andreas Vasdekis

We present an optical approach for intracellular delivery of molecules contained within oxidation-sensitive polymersomes. The photosensitizer ethyl eosin is associated with the polymersome membrane to oxidatively increase the hydrophilicity of the hydropho ...

American Chemical Society2012

Elastomer based tunable optofluidic devices

Demetri Psaltis, Andreas Vasdekis, Wuzhou Song

The synergetic integration of photonics and microfluidics has enabled a wide range of optofluidic devices that can be tuned based on various physical mechanisms. One such tuning mechanism can be realized based on the elasticity of polydimethylsiloxane (PDM ...

Royal Society of Chemistry2012

Light filter and method for using such filter

Julien Cuennet, Demetri Psaltis, Andreas Vasdekis

The invention concerns a light filter comprising a plate defined by a length along a direction x, a width along a direction y and a height along a direction z said plate including at least one chamber containing Liquid Crystals (LC) molecules and which is ...

2012

Optofluidic modulator based on peristaltic nematogen microflows

Julien Cuennet, Demetri Psaltis, Andreas Vasdekis, Luciano De Sio

Nematogens rotate by the application of external fields, thereby enabling optical modulation. This principle has had a profound impact on our daily lives through the plethora of liquid-crystal displays in use around us(1,2). However, the wider use of nemat ...

Nature Publishing Group2011

Light modulation enabled by liquid crystal microflows

Julien Cuennet, Demetri Psaltis, Andreas Vasdekis, Luciano De Sio

In a previous paper, 1 we proposed an optofluidic modulator based on peristaltic flow. A microchannel made of polydimethylsiloxane is filled with nematic liquid crystal molecules that align homeotropically in the steady state. Once we apply a periodic peri ...

2011

Silicon oxide deposition for enhanced optical switching in polydimethylsiloxane-liquid crystal hybrids

Julien Cuennet, Demetri Psaltis, Andreas Vasdekis, Luciano De Sio

We report an optical switch based on a diffraction grating by combining PDMS microstructures with a photo-responsive Nematic Liquid Crystal (NLC). The grating was realized via replica molding and was subsequently coated with a thin SiO layer. SiO induced a ...

2011

Optofluidic distributed feedback dye laser via evanescent gain

Demetri Psaltis, Andreas Vasdekis, Wuzhou Song

We demonstrate optofluidic evanescent dye lasers based on two types of solid distributed feedback (DFB) grating cavities- the first order linear DFB gratings which gives in-plane laser emitting and second order circular DFB gratings which gives surface las ...

Spie-Int Soc Optical Engineering, Po Box 10, Bellingham, Wa 98227-0010 Usa2010

Microfluidic assays for DNA manipulation based on a block copolymer immobilization strategy

Demetri Psaltis, Andreas Vasdekis

Methods to manipulate and visualize isolated DNA and oligonucleotide strands are important for investigation of their biophysics as well as their interactions with proteins. Herein, we report such a method by combining a block copolymer surface functionali ...

American Chemical Society2010

Tunable optofluidic dye laser with novel cavity

Demetri Psaltis, Andreas Vasdekis, Wuzhou Song

We present a pressured mediated tunable optofluidic dye laser with novel cavity. The dye laser chip was fabricated with Polydimethylsiloxane (PDMS) via replica molding and has none nano-features. It comprises a liquid waveguide and micro-scale air-gap cham ...

Spie-Int Soc Optical Engineering, Po Box 10, Bellingham, Wa 98227-0010 Usa2010

Surface optofluidics

Julien Cuennet, Demetri Psaltis, Jae-Woo Choi, Andreas Vasdekis, Wuzhou Song, Luciano De Sio

Surfaces -defined as the interfaces between solids and liquids- have attracted much attention in optics and biology, such as total internal reflection imaging (TIRF) and DNA microarrays. Within the context of optofluidics however, surfaces have received li ...

Spie-Int Soc Optical Engineering, Po Box 10, Bellingham, Wa 98227-0010 Usa2010

All-optical switching in an optofluidic polydimethylsiloxane: Liquid crystal grating defined by cast-molding

Julien Cuennet, Demetri Psaltis, Andreas Vasdekis, Luciano De Sio

We report an optofluidic photoswitchable grating, based on a polydimethylsiloxane periodic structure on a glass substrate, separated by a thin liquid crystal film. The polydimethylsiloxane microstructure was realized via high resolution replica molding and ...

2010

Micro-Air-Bag Actuated Tunable Optofluidic Elements

Demetri Psaltis, Jae-Woo Choi, Andreas Vasdekis, Wuzhou Song

We introduce for the first time a tuning mechanism for optofluidic devices by embedding a Micro-Air-Bag (MAB) actuator inside a microfluidic chip. Multiple tunable optical elements controlled through the pressure of compressed air were demonstrated. (C)200 ...

Ieee Service Center, 445 Hoes Lane, Po Box 1331, Piscataway, Nj 08855-1331 Usa2009