Dear all,

Many thanks to all those who answered my question concerning
biocompatible materials.  My original message was:

--------------------------

Dear MEMS community,

I am looking for a biocompatible material, which is deposited easily, by
spin-coating for instance, and offers good durability for microfluidic
devices.

1. Could anyone tell me what materials are considered to be
biocompatible?

2. Parylene C is often reported to be one of them, and it is said to be
vapour deposited.  Does this mean, it is deposited by Chemical Vapour
Deposition?

3. Are the following biocompatible: glass, silicone rubbers, PMMA?

Thank you very much for your time.

---------------------------------
The replies are displayed below:


From: Toby Rule   Save Address  Block Sender
To: Sung Jin , [email protected]
Subject: Re: Pyralene C and Biocompatible materials needed
Date: Tue, 23 Mar 1999 13:52:25 -0800

The following web pages have excellent information about using SU-8 for
microfluidic devices.  It is easily spun on and patterned using UV
light.  A multi-level process has been developed to form microchannels.
http://dmtwww.epfl.ch/ims/micsys/subtopics/projects/su8/EPON.html
http://dmtwww.epfl.ch/~mheuschk/

--------------------------------

From: "Karl Cazzini"   Save Address  Block Sender
To: "Sung Jin" , ,

Subject: RE: Pyralene C and Biocompatible materials needed
Date: Tue, 23 Mar 1999 17:20:07 -0500

See inset answers to some of your questions.

1. Could anyone tell me what materials are considered to be
biocompatible?
- PMMA (make solution 20 to 150 g/liter in Xylene, or other high boiling
point solvents)
- Polycarbonate (benzene, Iso butyl acetate, xylene)

3. Are the following biocompatible:
- glass (YES)
- silicone rubbers (YES, MOST OF THEM)
- PMMA? (GENERALLY YES, DEPENDS ON ADDITIVES)


--------------------------------

From: Thor Osborn   Save Address  Block Sender
To: 'Sung Jin' ,
"'[email protected]'"
Subject: RE: Pyralene C and Biocompatible materials needed
Date: Tue, 23 Mar 1999 17:41:14 -0800

Dear Sung Jin,

Biocompatibility is a complicated issue, and you need to consider what
you mean when you use the term "biocompatible".  All of the materials
you listed below could be considered biocompatible in some instances and
not in others.  On a practical basis I would recommend avoiding soft
polymers where possible for durability reasons.  You should also
consider the possibility of using silanizing reagents such as the many
offered in the Gelest catalog to "tailor" the surface chemistry of your
devices.  For reviews on biocompatibility in polymers I suggest you look
up the following authors, both in the biomaterials field and presently
employed as professors at the University of Washington in Seattle: Buddy
D. Ratner; Allan S. Hoffman.  Good luck.

Thor Osborn, Ph.D.
Manager, MEMS Processing, Microvision, Inc., 2203 Airport Way South,
Suite 100, Seattle, Washington 98134    TEL. (206) 623-7055 (Main
Office)    TEL. (206) 685-6649 (Fab Office)
FAX     (206) 467-8120

--------------------------------

From: "Dr. Mark W. Lund"   Save Address  Block
Sender
Reply-To: [email protected]
To: [email protected], [email protected]
CC: [email protected], [email protected]
Subject: RE: Pyralene C and Biocompatible materials needed
Date: Tue, 23 Mar 1999 22:39:55 MST/MDT

Dear Sung Jin,
Parylene C might be considered to be vacuum deposited.  The dimer is
sublimed, then this gas is passed through a furnace at 700 degrees C,
where the dimer breaks down into monomer molecules.  The monomer gas is
then passed into the coating chamber at room temperature.  Three
monomers must come together to start the polymerization, which is nearly
impossible in the gas, but likely on surfaces, so the gas can penetrate
into every nook and cranny, then polymerize on the surface.  Thus it can
be made thin, conformal, and complete.  It is very intert (I mean inert)
and strong.

best regards, mark
Mark W. Lund, PhD
VP Engineering  >> Soft X-ray Web page http://www.moxtek.com<<
MOXTEK, Inc. , 452 West 1260 North, Orem UT 84057       801-225-0930
FAX 801-221-1121
[email protected]

--------------------------------

From: Torsten Eggers   Save Address  Block
Sender
To: "'Sung Jin'" 
Subject: AW: Pyralene C and Biocompatible materials needed
Date: Wed, 24 Mar 1999 08:46:31 +-100

----------
Von:  Sung Jin[SMTP:[email protected]]
Gesendet: Donnerstag, 18. März 1999 13:05

1. Could anyone tell me what materials are considered to be
biocompatible?
PMMA, PUR, PTFE, glass, silicone, titanium, Si3N4 and other ceramics

3. Are the following biocompatible: glass, silicone rubbers, PMMA?
Silicone: Nusil delivers biocompatible silicone
PMMA is used for intraocular lenses ! (www.morcher.com) !
glass: not every glass, but most I asume

Torsten Eggers

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