1) what's the application? 2) what's your specification? 3) what's wrong with plastic or similar? That is, what in your spec demands something non-plastic? 4) what's 'right' with germanium oxide? My goodness, that's an exotic material. Growing a stable oxide on single-crystal germanium is extremely difficult, requiring both I think high pressure and high temperature (the original investigations date to the 1950s), and even then the oxide is pretty much crap as an electrical insulator, and who knows about its mechanical properties. 5) people have built a wide variety of pumps and pressure sensors out of plastic. I'm less sure about glass (can't recall any offhand, although I've built glass membranes, and have seen some publication of same in the literature). 6) Far more pumps and pressure sensors have been built out of silicon, or combinations of silicon and glass. Quartz (crystalline silicon dioxide) has been used for resonant pressure sensors for a long time, although not so much in MEMS. 7) Alignment of channels can be done using KOH-etched silicon at a specified width, then use optical fiber as a 'guide' for alignment on bonding. Numerous schemes exist for the actual bonding (Si-glass, Si-Si, glass-glass, using metal as intermediary bonding layer; Goran Stemme at KTH and his colleagues used a particular bonding resin with good results). This is a low-cost and relatively high precision alignment scheme, and has been published in the literature. 8) why a cylindrical channel? Look around on Google scholar for references on materials and processing. Peter Woias has a particularly good review on micropumps, about 6-8 years ago. But, there's been considerable new work in the interim. Look at the journal Lab on a Chip, and the proceedings from the micro-TAS conference. If you want to prototype something quickly, look at Steve Quake's foundry at Stanford. You could build a pneumatically-actuated bucket-brigade pump out of his tech, and kluge up a pressure sensor from deflection of a PDMS membrane. --- Albert K. Henning, PhD Director of MEMS Technology NanoInk, Inc. 215 E. Hacienda Avenue Campbell, CA 95008 408-379-9069 ext 101 ahenning@nanoink.net -----Original Message----- From: Nathan McCorkle [mailto:nmz787@gmail.com] Sent: Saturday, October 03, 2009 2:26 AM To: mems-talk@memsnet.org; skkemc@rit.edu; josan_92@yahoo.com; diybio Subject: [mems-talk] I want to build a pressure sensor and micropump I want to know how I would create a pressure sensor and pump for moving and detecting pressures along 30 - 75 uM cylindrical (or as near as possible) channels, with two layers most likely glued together to form the cylinder. This could be done on silicon, but I would like to work with something optically clear, glass, germanium oxide? Can I get germanium wafers, if so how much are they and where do I get them? And second, could I build I germanium oxide wafer by deposition of something? Can germanium fuse with silicon to allow the channels to be clear while the electronics and pumps/sensors are in god old silicon? Right now the guy I am going to work training with is making simple channels in lexan (polycarbonate) from home depot or somewhere, and his "wafer" (cut from a sheet in a machine shop) was pretty scratched up. He never did a clean etch on it, so I am pretty sure the working device yield is pretty low. Alignment of layers could be a pain as well if working devices don't match. I couldn't find much searching for Ge/GeO2 wafers or GeO2 growth, but I found the price to be $3/g, GeO2 is 4.228g/cm^3, so for less than $30 I could have quite a bit of high quality real estate to develop on. We do have a glass dept here at RIT if we needed some way to make a plate from molten germanium (maybe), unless there is another way to do this. Let me know what you think, I am new at this. link on etching glass: http://mail.mems-exchange.org/pipermail/mems-talk/1996-July/000672.html unanswered question about how to etch GeO2 http://mail.mems-exchange.org/pipermail/mems-talk/2005-February/014949.h tml -Nathan -- Nathan McCorkle Rochester Institute of Technology College of Science, Biotechnology/Bioinformatics