Hi Tsoll,

You can use grayscale mask photolithography to generate slop in SU8 to create
your master mold for PDMS...good luck
---

Waseem Khan Raja
Postdoc Fellow
Tufts Unviversity
Medford, MA, USA

--- On Mon, 2/28/11, Dr. Holger Becker  wrote:

From: Dr. Holger Becker 
Subject: Re: [mems-talk] Sloped microchannel
To: "'Tsoll Doiiu'" , "'General MEMS discussion'" 
Date: Monday, February 28, 2011, 11:42 AM

Hi Tsoll,

the only reasonable way I know of making such sloped channels is by
mechanical micromachining the master, e.g. in PMMA. Precision machining
nowadays can make you extremely precise structures (lateral and vertical
geometry +-1 µm), it usually takes a quite expensive bit of machinery to do
so (e.g. Kern, Precitech, Kugler) but the results are quite amazing. We
regularly use precision machining for mold inserts for injection molding of
microfluidic channels. The critical bit might be surface roughness, which is
higher compared to lithographically defined channels but there are ways of
mechanical or chemical polish.

With best regards
Holger