Research Projects

Ph.D research

My Ph.D research topic is “Cell-free Artificial Photosynthesis System”. I participated The objective of this research is to create a cell-free artificial platform for harvesting light energy and transforming the energy to organic compounds. In order to achieve this objective, we take the approach of mimicking the photosynthetic processes of a di-cotyledons plant leaf and integrating them into a compact system using microfabrication technology. We envision integrating the “artificial leaves” to create a compact energy harvesting system with high efficiency. (1) Light reaction are realized in a microfluidic platform that consists of two fluid chambers separated by a planar membrane with embedded proteins that convert light energy into ATP; (2) Dark reaction are realized in another microfluidic platform that consists of two chambers (one for liquid containing ATP and the other for air flow) separated by a membrane that can transport CO₂ from the air to the liquid chamber; (3) Glucose synthesis and storage unit were developed by mimicking sponge mesophyll found in a leaf; (4) Interconnection and integration of the above-mentioned three key components will be investigated to generate a complete cell-free artificial platform for effective energy harvesting. This research brings together expertise in advanced manufacturing (bio- and microfabrication, additive manufacturing), biochemistry and biomaterials, and system control and integration.

Postdoctoral Research (Virginia Tech)

My work focused on studying the bioelectrical and biomechanical properties of breast cancer cells and circulating tumor cells (CTCs) using microfluidic techniques. The objective of this work is to develop a high-throughput microfluidic chip to expose cells to sequential deformations and to identify differential biomechanical and bioelectrical properties of tumor and normal breast cells. This work results in “mechanical modulatory signatures” that quantify degrees of resistance of breast cells in response to applied sequential forces. We have completed tests of human breast tumor cell lines and through our collaboration with a clinical team, and initiated testing of primary breast cells derived from patient biopsy samples. The application of the work addresses the important challenges of distinguishing normal breast cells from tumor cells with metastatic potential, and to use these devices to identify drug resistant tumor cells which could help physicians choose appropriate drug treatments on an individual patient basis. Aggressive cancer cells, which possess a less organized cytoskeleton, often have acquired the ability to deform and squeeze through complex tissue matrices and gain access to the circulatory and lymphatic systems, where they can spread to distant sites and establish secondary tumors. This suggests that the metastatic potential of cancer cells is related to their mechanical properties. These studies suggest that cell biophysical properties can be used as potential “label-free” biomarkers to provide more detailed cancer diagnoses. We developed a platform for cell analysis by surface enhanced Raman scattering (SERS). We found that the Raman Effect can detect the progress of metastatic breast cancer cell mitosis procedure at single cell level. In addition, nano-antennas for Raman scattering can collect bimolecular information of cells at different cell cycles. The biophysical attributes are able to distinguish cancerous and normal cells, or even different subtypes of cancer cells. Furthermore, the anti-cancer drug treatment studies on the cancer cells can also be achieved on these kinds of multi-modal microfluidic techniques.

Postdoctoral Research (University of Notre Dame)

In this project, we aim to explore the potential of coupled oscillator networks made of living cardiac muscle cells, or bio-oscillators, as collective computing components for solving computationally hard problems such as optimization, learning and inference tasks. Cardiac muscle cells are electrically active components that can initiate and relay electrical signals without loss. More interestingly, they spontaneously beat (i.e. oscillate) at a stable pace, and when coupled with each other, they synchronize to a locked, steady frequency. We started with a pair of coupled bio-oscillators and characterize their synchronization behavior. Then we investigated a lithography based microfabrication method to scale up to complex networks with many nodes and edges. In order to demonstrate the communication between two clusters of cardiomyocytes (CMs), we patterned the CMs into a pair of nodes of 100~1000 CM cells with a bridge connection. CMs, the major functional cell of the myocardium through its ability to fire action potentials, constitute only one-third of the population, while the rest were made of non-excitable cells such as the cardiac fibroblasts (CFs). Conduction across the myocardium and dynamic function of the CMs were influenced by the various factors including CM-CF crosstalk. We designed and fabricated novel microdevices to fulfill the function of detection of CM action potentials with adjustable micropatterns with the scale of 100~1000 cells. This project is aiming to build a bio-nano hybrid computational component with data processing capabilities and microelectrode array read outputs for programmable and configurable computing.