Separation of biologically active molecules (BAMs) is a problem for the pharmaceutical and biotechnology industries. Current technologies addressing this problem require too many techniques, toxic additives, and time to filter the desired materials. As a result, a new technology is needed. The objective of this work is to contribute to the development of a device that can separate 0.5 nm to 500 nm sized BAMs. A diaphragm valve is proposed that can control a gap created by two parallel flat surfaces. Position control is achieved by means of a piezoelectric actuator and a capacitive sensor. Modularity was also part of design considerations to address issues of eventual biocompatibility breakdown. Preliminary experiments indicate that gap separation can be controlled to increments of 0.2 nm.

1.
Greenwich University, 1992. Techniques Used in Bioproduct Analysis. Butterworth-Heinemann. Chapter 5, Written by R. Cannell.
2.
Wallin, R. F., 1998. “Biocompatibility guidelines, using eto with parylene”. Medical Device & Diagnostic Industry Magazine, January, p. 82. www.devicelink.com/mddi/archive/98/01/017.html.
3.
Shah, M., 2002. email, November.
4.
White, J., 2003. “The nanogate:nanoscale flow control”. PhD thesis, Massachusetts Institute of Technology, 77 Massachusetts Avenue Cambridge,MA 02139, May.
5.
Israelachvili, J., 2003. http://squid.ucsb.edu/ sfalab/mark-II.html, January.
6.
Gutierrez, M., 2004. “Size adjustable separation of biologically active molecules”. Master’s thesis, Massachusetts Institute of Technology, 77 Massachusetts Avenue Cambridge, MA 02139, June.
7.
Stancil, B., 2002. “Design of a programmable filter for macromolecules”. Master’s thesis, Massachusetts Institute of Technology, 77 Massachusetts Avenue Cambridge,MA 02139, June.
8.
Freitas Jr., R. A., 1999. Nanomedicine, Vol. 1. Landes Bioscience, October. http://www.foresight.org/Nanomedicine/.
9.
Chakraborty, I., Tang, W. C., Bame, D., and Tang, T. K., 2001. Normally closed, piezoelectrically actuated microvalve. Tech. rep., NASA and Jet Propulsion Laboratory, January. http://www.nasatech.com/Briefs/Jan01/NPO20782.html.
10.
Walter D. Pilkey. Formulas for Stress, Strain, and Structural Matrices. Wiley Interscience, 1994.
11.
J.M. Paros and L. Weisbord. How to design flexure hinges. Machine Design, pages 151–156, November 1965.
12.
Lai
S.
,
Lee
L. J.
,
Yu
L.
,
Koelling
K. W.
, and
Madou
M. J.
,
2002
. “
Micro- and nano-fabricaiton of polymer based microfluidic platforms for biomems applications
”. In
BioMEMS and Bionanotechnology
, L. P. L. Manginell, Ronald P. Jeffrey T. Borenstein and P. J. Hesketh, eds., Vol.
729
, Materials Research Society, Materials Research Society, pp.
17
27
.
13.
Zhang
,
Miqin
T. D.
, and
Ferrari
M.
,
1998
. “
Proteins and cells on peg immobilized silicon surfaces
”.
Biomaterials
,
19
(
10)
, May, pp.
953
960
.
14.
Sharma
,
Sadhana
K. C. P.
, and
Desai
T. A.
,
2002
. “
Controlling nonspecific protein interactions in silicon biomicrosystems with nanostructured poly(ethylene glycol) films
”.
Langmuir
,
18
(
23)
, November 12, pp.
8728
8731
.
15.
Alcantar
N. A.
,
Aydil
E. S.
, and
Israelachvili
J. N.
,
2000
. “
Polyethylene glycol-coated biocompatible surfaces
”.
Journal of Biomedical Materials Research
,
51
(
3)
, September, pp.
343
351
.
16.
Papra
A.
,
Bernard
A.
,
Juncker
D.
,
Larsen
N. B.
,
Michel
B.
, and
Delamarche
E.
,
2001
. “
Microfluidic networks made of poly(dimethylsiloxane), si, and au coated with polyethylene glycol for patterning proteins onto surfaces
”.
Langmuir
,
17
(
13)
, June, pp.
4090
1095
.
17.
Shilpiekandula, V., and Youcef-Toumi, K. “Modeling and control of a programmable filter for separation of biologically active molecules”. In Proceedings of American Control Conference, pp. 394–399.
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