Author: Marcela Mireles

Microtechnologies for cells Phototunable Spatiotemporal Presentation of Viscoelastic and Adhesive Cues in HA Hydrogels Erica Hui1, Kathryn I. Gimeno2, Thomas H. Barker2, Steven R. Caliari1,2 Department of Chemical Engineering, Department of Biomedical Engineering, University of Virginia https://www.biorxiv.org/content/10.1101/646778v1.full Developed a hyaluronic acid (HA) hydrogel system to study the role that spatially-patterned matrix mechanical (viscoelastic) and adhesive…

Hello everyone! this post describes how we are going about determining the size cut-off of the membranes we make through nanosphere lithography. These are 120 nm thick silicon nitride membranes with controlled pore size between 320 and 80 nm. A polymeric scaffold is placed on them to increase robustness. The scaffold is a square grid…

Cody Soule (MS student) developed/applied a protocol to functionalize the surface of a silicon oxide membrane. The process selectively attaches PNIPAM to the surface of the membrane, maintaining the pore characteristics unchanged. PNIPAM undergoes a configuration transition when going from 37C to RT, from collapsed to extended. It has been previously used to lift-off confluent…

Hello everyone, Aslan and I attended talks regarding EVs enrichment which can be divided into two broad categories depending on their ability to recover and reuse the EVS or not. There is a recent review called “New technologies for analysis of extracellular vesicles” published this year on Chemical Reviews. Their breakdown of the different methods…

We are working on finishing up a manuscript on our nanosphere lithography work. this post shows some of the figures for said publication. This paper includes work done with 300 and 200 nm NS as preliminary work, and then focuses on 200 nm NS only to evaluate the porous pattern obtained. From the data presented,…

Here is a summary of some of the talks I attended at BMES 2017, mainly from the Nano and Micro- technologies track. This is an ongoing post, I will post more comments, links, and figures. Anna Kalmykov (Tzahi Cohen-Karni) Carnegie Mellon University: 3D Nanosensors for Electrical Interrogations of Engineered Micro-tissues. Overall synthesis of nanostructures to be used…

The plot below shows a calibration curve to calculate the etching time needed during the RIE step (used to reduce the size of the nanospheres) to obtain a desired pore size. The membranes were patterned from nanospheres with a nominal diameter of 300 nm., we know from SEM images that their actual size is 340…

This post offers an update on membrane fabrication through nanosphere lithography (NSL), describing in more detail the releasing step as well as the membrane integration into PDMS devices. Membrane lift-off is achieved by dissolving a ZnO film underneath the membrane. After fabrication the sample is immersed in 1M HCl solution. The figure below shows a…

This post includes some optical and SEM micrographs of a SiO2 membrane patterned by nansosphere lithography using 300 nm polystyrene beads. An SU-8 microgrid was deposited on top and the membrane was released by dissolving a bottom layer of ZnO. After the release, the membrane is rinsed in water and transferred to a clean substrate….

Thanks to UR cleanroom and Jim Mitchell, we finally have a better way to deposit the ZnO film that our fabrication process uses as sacrificial layer. Below is a quick comparison of the previous ZnO deposited by sol-gel and the new ZnO deposited by sputtering at UR. Hopefully, if you look close enough (or far…