Difference between revisions of "13.06.2024 - NA"
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* the NOA89 flue is definitely very flowy and water-like, and seeps through the stencil very easily. I am excited to see if the patterns will show up as they should, or if the glue is simply not viscous enough to make any of the patterns come through... | * the NOA89 flue is definitely very flowy and water-like, and seeps through the stencil very easily. I am excited to see if the patterns will show up as they should, or if the glue is simply not viscous enough to make any of the patterns come through... | ||
* since the glue is not as viscous, it is more difficult to make a frame around the stencil. The frame is quite important, as it will be peeled later once the fibronectin has been places inside of the patterns. | * since the glue is not as viscous, it is more difficult to make a frame around the stencil. The frame is quite important, as it will be peeled later once the fibronectin has been places inside of the patterns. | ||
| − | '''<u>Reflections after the experiment:</u>''' | + | '''<u>Reflections and final outcomes after the experiment:</u>''' |
| − | + | * NOA89 glue did not make the stenciling protocol more successful - the patters do not come through like they are supposed to. | |
| − | ' | + | * The layer of the glue was too thin, and did not peal off the PDMS stamp like it usually does - it was still stuck to it, and hence none of the patters were transferred to the petri dish. |
| + | * Maybe one way around it would be to use glue that has viscosity that is between NOA73 and NOA89 - DKD found some NOA83 glue, which I might try to use and see if it helps with stenciling. | ||
| + | * In conclusion, I think that all of this is happening due to very small intern-pattern distance, which makes it difficult for viscous glue to get through the patterns. To test this hypothesis, I tried stenciling my usual bigger patterns from other experiments with NOA89, and it worked indeed. The stencil was much thinner and more delicate to handle (easier to break as the layer of glue was much thinner and the cured NOA89 glue was much softer than cured NOA73 glue), but at least the patters got through. So, I am suspecting that the glue's viscosity is not the biggest factor - reducing the viscosity still did not help us get around the issue of getting the glue to get through the pattern. We might need to either 1) reconsider other patters with larger intern-pattern distance or 2) developed another technique or talk to someone who has micropatterned using stenciling for such small patterns. | ||
Latest revision as of 10:30, 17 June 2024
Working on NOCC patterns made by Ali Aslan Demir (AAD). Based on previous experience, I have a feeling that the patterns did not transfer that well during curing due to the UV glue being too viscous and not getting through the entire stencil via capillary forces. Three tactics to combat this have been suggested:
- Use less viscous glue. At the moment I am using NOA73, but DKD has recently purchased NOA89, which is the least viscous of the glues that they have. Using less viscous glue might help with glue getting through all of the small patterns and spreading across the entire surface of the stencil.
- Let stencils sit for longer to let capillary forces do their job properly instead of curing too quickly.
- Covering the stencil with aluminum when wicking (letting glue get through due to capillary forces) so that the glue does not cure under normal light too quickly. Since the layer of the glue is very thin, normal light might affect it and not let it get through the entire area.
In today's experiments, I will be trying to keep every step of the protocol the same except for the glue. I will use the new NOA89 glue and see if it works better than NOA73.
Notes during experiment:
- the NOA89 flue is definitely very flowy and water-like, and seeps through the stencil very easily. I am excited to see if the patterns will show up as they should, or if the glue is simply not viscous enough to make any of the patterns come through...
- since the glue is not as viscous, it is more difficult to make a frame around the stencil. The frame is quite important, as it will be peeled later once the fibronectin has been places inside of the patterns.
Reflections and final outcomes after the experiment:
- NOA89 glue did not make the stenciling protocol more successful - the patters do not come through like they are supposed to.
- The layer of the glue was too thin, and did not peal off the PDMS stamp like it usually does - it was still stuck to it, and hence none of the patters were transferred to the petri dish.
- Maybe one way around it would be to use glue that has viscosity that is between NOA73 and NOA89 - DKD found some NOA83 glue, which I might try to use and see if it helps with stenciling.
- In conclusion, I think that all of this is happening due to very small intern-pattern distance, which makes it difficult for viscous glue to get through the patterns. To test this hypothesis, I tried stenciling my usual bigger patterns from other experiments with NOA89, and it worked indeed. The stencil was much thinner and more delicate to handle (easier to break as the layer of glue was much thinner and the cured NOA89 glue was much softer than cured NOA73 glue), but at least the patters got through. So, I am suspecting that the glue's viscosity is not the biggest factor - reducing the viscosity still did not help us get around the issue of getting the glue to get through the pattern. We might need to either 1) reconsider other patters with larger intern-pattern distance or 2) developed another technique or talk to someone who has micropatterned using stenciling for such small patterns.
