I have been trying to verify that my MgF2 material is cytocompatible (e.g. no different than tissue culture plastic), and attempted Live/Dead staining to confirm. The following images are from P6 HUVECs with Invitrogen L3224 Live/Dead stain on MgF2, NPN, and tissue culture plastic after ~96 hours. The devices were initially seeded at 5e5 cells/mL,…
My recent work has focused on wetting the inner portion of an attocavity with isobaric cooling to create condensation. We are trying to attack the problem of wetting through the nanomembrane without breaking the membrane. A perfectly dry membrane will always rupture before the critical radius for wetting the backside of the membrane is achieved. To…
Summary and Instructional video The simplest way to get something wet is to allow water to condense on the surface of the something. In our case, we have a number of nanocavities (~ 0.1 femtoliters) with porous tents over them. The easiest thing to do is simply chill the substrates down to allow condensation to form….
I wrote about my experiences tenting nanomembranes here. I delaminated NPN material across a bunch of substrates and found that the film would actually form a nanocavity if spread across a sufficiently small surface (I estimated it to be 1-2 microns over a 50 nm height difference). Simpore fabricated a number of small substrates with varying…
I was not entirely satisfied with the amount of data that I received from my last burst pressure wafer, so I processed another wafer. This wafer had some yield loss initially, as well as window sizes that were slightly smaller than expected (by about 50 microns). We expect the mechanical strength of the windows to…
In my recent tenting posts, the membrane has shown that it can deform and wrap around edges. I wanted to follow up on this phenomenon and see if we could get a contiguous sheet of membrane around a PDMS edge (not completely sharp). If we can get some membranes around a ~90 sidewall, we could have…
The NPN tenting mechanism I’ve described in a few different posts has relied solely on mechanical technique. I poke the substrate with tweezers, or delaminate it with high electrical forces, or heat it up and let it contract while in contact with each other. It would scale very poorly if we tried to make this…
From my last two posts (Anodic Bonding, Ozone Bonding), it is clear that we have some sort of bonding going on between the freestanding membrane and the posts intended to support the membrane. However, we do not understand the nature of the transfer. To gain more insight into this process, I took more SEMs of…
We have wondered if we can skip anodic bonding and bond the chips using our UV ozone process. There are pros and cons to this approach, mainly that the setup and procedure is easy, but the contact and alignment is difficult. So I gave it a try. Here are a few SEMs of ozone bonded…
Previous posts: Anodic Bonding Theory, Anodic Bonding Setup I had originally hoped there would be enough residual impurity in the oxide layer to create a direct bond with Vincent’s chips. This was a foolish hope. Pyrex is at least 4-5% doping and standard p-doped silicon wafers are 5-6 orders of magnitude less than that, with…