Chopper-modulated gas chromatography electroantennography enabled using high-temperature MEMS flow control device.

We report the design, fabrication and characterization of a microelectromechanical systems (MEMS) flow control device for gas chromatography (GC) with the capability of sustaining high-temperature environments. We further demonstrate the use of this new device in a novel MEMS chopper-modulated gas chromatography-electroantennography (MEMS-GC-EAG) system to identify specific volatile organic compounds (VOCs) at extremely low concentrations. The device integrates four pneumatically actuated microvalves constructed via thermocompression bonding of the polyimide membrane between two glass substrates with microstructures.

G-Fresnel smartphone spectrometer.

We report a smartphone spectrometer with nanometer resolution working in the visible range. A G-Fresnel device with the dual functionality of focusing and dispersion is used to enable miniaturization. Proof of principle application to Bradford assay of protein concentration is also demonstrated.

On-demand one-step synthesis of monodisperse functional polymeric microspheres with droplet microfluidics.

A simple and robust method for one-step synthesis of monodisperse functional polymeric microspheres was established by generation of reversed microemulsion droplets in aqueous phase inside microfluidic chips and controlled evaporation of the organic solvent. Using this method, water-soluble nanomaterials can be easily encapsulated into biodegradable Poly(D,L-lactic-co-glycolic acid) (PLGA) to form functional microspheres. By controlling the flow rate of microemulsion phase, PLGA polymeric microspheres with narrow size distribution and diameters in the range of ∼50-100 μm were obtained.

Separable bilayer microfiltration device for viable label-free enrichment of circulating tumour cells.

The analysis of circulating tumour cells (CTCs) in cancer patients could provide important information for therapeutic management. Enrichment of viable CTCs could permit performance of functional analyses on CTCs to broaden understanding of metastatic disease. However, this has not been widely accomplished.

Facile synthesis of magnetic mesoporous hollow carbon microspheres for rapid capture of low-concentration peptides.

Mesoporous and hollow carbon microspheres embedded with magnetic nanoparticles (denoted as MHM) were prepared via a facile self-sacrificial method for rapid capture of low-abundant peptides from complex biological samples. The morphology, structure, surface property, and magnetism were well-characterized. The hollow magnetic carbon microspheres have a saturation magnetization value of 130.

Flexible micro spring array device for high-throughput enrichment of viable circulating tumor cells.

Background: The dissemination of circulating tumor cells (CTCs) that cause metastases in distant organs accounts for the majority of cancer-related deaths. CTCs have been established as a cancer biomarker of known prognostic value. The enrichment of viable CTCs for ex vivo analysis could further improve cancer diagnosis and guide treatment selection.

Viable circulating tumor cell enrichment by flexible micro spring array.

We demonstrated a high throughput versatile platform capable of isolating circulating tumor cells (CTCs) from clinically relevant volumes of blood while preserving their viability and ability to proliferate. The enrichment is based on the fact that CTCs are larger compared with normal blood cells. The incorporated system allows size-based separation of CTCs at the micro-scale, while taking advantage of a high throughput and rapid processing speed.

An implantable Fabry-Pérot pressure sensor fabricated on left ventricular assist device for heart failure.

Continuous flow left ventricular assist devices (LVADs) are commonly used as bridge-to-transplantation or destination therapy for heart failure patients. However, non-optimal pumping speeds can reduce the efficacy of circulatory support or cause dangerous ventricular arrhythmias. Optimal flow control for continuous flow LVADs has not been defined and calls for an implantable pressure sensor integrated with the LVAD for real-time feedback control of pump speed based on ventricular pressure.