Homebrew PCBs

--- In Homebrew_PCBs@yahoogroups.com, "jc805sb" <jc805sb@...> wrote:
>
> --- In Homebrew_PCBs@yahoogroups.com, "javaguy11111" <javaguy11111@> wrote:
> >
> >  Are you trying to mount MEMs devices on a pcb or using a pcb for making MEMs devices?
> > 
> 
> I am etching copper patterns which operate as the MEMS
> (the field calls it MEMS although there's nothing mechanical).
> I have pictures on my blog here,
> http://88proof.com/synthetic_biology/blog/archives/280
> 
> The pictures show pretty poor etch results which 
> I am trying to improve using the best SMT techniques first.
> Pad size/spacing is 1mm x 1mm with 0.125mm gap, or smaller!
> 
> Other researchers in the field have made similar MEMS
> on flexi boards.  I can list some interesting articles
> if interested.  These boards move liquid droplets across
> surfaces (even vertical surfaces).  Though this requires
> maybe >+1000V.
> 
> Something tangentially interesting, some researchers used
> an "aborted etch" method with multiple dips in etch and
> multiple mask steps, to make copper traces of different 
> heights.  Not useful for standard PCB however they were
> able to use it as MEMS for nanoparticle separation.
> They used ferric chloride as the etchant and found it 
> to be a linear etch, so the copper "steps" could be 
> precisely made.   These steps were 10um to 50um or 
> something.
> 
> 

I have some hopes of doing some homebrew MEMs experimentation. I am just getting back into board building and starting to do some work with photoresist. Once I get my technique refined, I will probably jump into a little MEMs experimentation.

I did try a little electrowetting experimentation a year of so ago when I first heard about it. Nothing too sophisticated, just tried to verify the concept. Unfortunately it did not really work for me.

I have often thought of starting a homebrew MEMs/microfluidics group similar to this group, but I really would not have the time to maintain it.