Milagros Fernandez Oromendia is from both Buenos Aires, Argentina and the suburbs of St.Paul, Minnesota, where she is currently studying Biomedical Engineering at the University of Minnesota- Twin Cities. This summer, she is working in Dr. Dan Huh’s lab on two projects. First, she will be working on the placenta-on-a-chip model and using it to see how shear stress affects the differentiation of trophoblasts (placenta specific cells). Next, she will be working on the development of a continuous stiffness measuring sensing device for engineered tissues. After graduation Mili plans on pursing a graduate degree in Biomedical Engineering.
Integrated Sensing for Lung Fibrosis-on-a-Chip
Lung fibrosis is a deadly disease that currently affects over 130,000 people in the United States. This disease is characterized by the stiffening of the lung tissue caused by the excess fibroblast deposition of extracellular matrix. Although there are currently two pharmaceuticals on the market to help reduce symptoms and slow down the progression of the disease, there continues to be no cure. Furthermore, there are still many gaps in our understanding of lung fibrosis as well as a lack of good in vitro models of the disease. Therefore, we developed an integrated sensor organ-on-a-chip model that allows for real time monitoring of the functional properties [ex. Contract stiffness] of engineered cell hydrogel constructs. The device fabrication process includes the creation of a PDMS deformable membrane followed by screen printing a carbon black-PDMS mixture over the membrane. After fabrication, the devices were calibrated using in-house engineered circuity, an ammeter, a pressure sensor and pump, and microscopy. In order to optimize the sensitivity of the sensors, we tested multiple carbon black to PDMS concentrations to find a ratio that was conductive enough to transmit a signal even when stretched, but resistive enough that even slight changes in membrane deformation can be detected. The optimal concentration for sensor sensitivity as found to be a 12% Carbon black to PDMS by weight ratio. Future work involves further optimization of the sensor geometry as well as the addition of hydrogels to the device.