Re: Nano and RP - is this small enough?

Date: Tue Aug 28 2001 - 21:05:36 EEST

The ability of this system to make small objects that can fit inside a blood
vessel is only significant if the object can withstand the high stresses of
the body on such a small object. Researchers at UC Berkeley also looked at
using MEMS devices for Biomechanical means to choke off a tumor's blood
supply locally with damaging the surrounding healthy tissue. The problem was
two fold in making this happen: (1) you had to be able to get it to right
site before activating the machines to block the capillaries feeding the
tumor. (2) you had to get it there in one piece.

Pound for pound Polycrystalline silicon is way stronger than steel (about
10X), but because it has a small cross-sectional area, a very small load of a
few pounds of force translates to 100s of thousands PSI stress. Thus a
vessel attempting to navigate the human cardiovascular system cannot go
through the heart while it is pumping. Then there the stresses from just

The proposed method for getting these vessels to right place before
activating them was to use antigens as coatings to attract the vessel to
right spot. The question is for the applications of these small RP objects
is can they withstand the stresses better than polysilicon structures? Can
they be welded together and assembled into more complex structures that are
structurally sound? Can they be coated with biological materials and still
be a benign substrate (plastics are organic chemical derivatives)?

As for optical lithography, deep UV has been available for a number of years.
 Still it may have promise in the area of photopolymer masks used for making
integrated circuit chips.

The eventual benefit to RP is that machines will be able to be made cheaper
enough and small enough to be affordable for a home based system. The
limiting cost component is the complex optical focusing system required for a
laser-based system.

For broadbased RP intro into nonindustrial environment, there must be a
killer application for the mass market RP system.

Scott Taper
VP, Business Development
ParaMorph Systems Corp. (an SRI/Phase 2 Automation venture)
Business: 650-444-2572
Technology Commercialization Consulting
Business: 650-444-2572

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