High temperature MEMS valves for GC-based VOC detection
We designed and fabricated a MEMS flow control device for gas chromatography (GC) with the capability of sustaining high-temperature environments. We demonstrated 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) secreted by insects at extremely low concentrations.
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Microfluidic device for functional microsphere synthesis
We developed a simple and robust method for one-step synthesis of monodisperse functional polymeric microspheres by generation of reversed microemulsion droplets in aqueous phase inside a microfluidic device 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. As a demonstration of the versatility of the approach, high-quality fluorescent quantum dots of various emission spectrums, superparamagnetic iron oxide nanoparticles and water-soluble carbon nanotubes were used to synthesize fluorescent, magnetic and CNT-containing polymeric microspheres, respectively.
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On-Demand One-Step Synthesis of Monodisperse Functional Polymeric Microspheres with Droplet Microfluidics, X. Yu, G. Cheng, M.-D. Zhou & S.-Y. Zheng, Langmuir, 31, 3982-3992, 2015. [Link]
Bone chip to study bone metastasis
Bone metastasis occurs at approximately 70% frequency in metastatic breast cancer and most women who die of metastatic breast cancer have bone metastases. We developed a bone-on-a-chip for spontaneous growth of a 3D, mineralized, collagenous bone tissue. Based on the principle of simultaneous-growth-dialysis, mature osteoblastic tissue containing heavily mineralized collagen fibers naturally formed in 30 days without the aid of differentiation agents. Moreover, we examined co-culture of metastatic human breast cancer cells with osteoblastic tissues. The new bone-on-a-chip design not only increases experimental throughput while reducing fabrication cost by miniaturization, but also maximizes the chances of cancer cell interaction with bone matrix of a concentrated surface area and facilitates easy, frequent observation.
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A spontaneous 3D bone-on-a-chip for bone metastasis study of breast cancer cells, S. Hao, L. Ha, G. Cheng, Y. Wan, Y. Xia, D. M. Sosnoski, A. M. Mastro, and S.-Y. Zheng, Small, 14, 1702787, 2018. [Link] [Physicsworld]