The NanoGate: A device for nanometer

control of the separation between two plates Prof. Alex Slocum

Prof. Jeff Lang

Hong Ma

Alex Sprunt

James White

Xue’en Yang

Massachusetts Institute of Technologyhttp://pergatory.mit.edu slocum@mit.edu

June 28, 2002

Nanogate• The Nanogate is a device that precisely meters the flow of tiny amounts of fluid.

– Precise control of the flow restriction is accomplished by deflecting a highly polished cantilevered plate.

– The opening is adjustable on a sub-nanometer scale, limited by the roughness of the polished plates.

• The Nanogate can be fabricated on a macro-, meso- or micro- (MEMs) scale.

– This research grew out of understanding of flow metering garnered from years of hydrostatic bearing research

• This research was initially funded by an NSF award, number 9900792

• The Center for Bits and Atoms is funding the continued development of the Nanogate technology as it evolves into the FractureGate

Possible fuel injector application?

Surface Creation• Fracture

– Must be done slowly

– Surfaces will be matched (no plasticity)

– Even “mirror” regions not atomically smooth

• Stress Corrosion Cracking

– 0.12 nm surface roughness independent of crystal orientation

– K. Minoshima, S. Inoue, T. Terada, and K. Komai, “Influence of Specimen Size and Sub-Micron Notch on the Fracture Behavior of Single Crystal Silicon Microelements and Nanoscopic AFM Damage Evaluation,” Mat. Res. Soc. Symp. Vol. 546, pp. 15-20, 1999.

Polished Stress Cracked

J. Connally and S. Brown, “Micromechanical Fatigue Testing,” Experimental Mechanics, Vol 33, No. 2 (June 1993)

Concept• Etch manifold wafer

• Bond wafers

• DRIE through

• Break w/external actuator– =FractureGate

In silicon, surfaces would be matable

F FG ate

C hannel

W afers

Bench Level Experiment• Insight into variables that affect

stress corrosion cracking, i.e. stress, humidity, temperature

• AFM study of the surfaces

Zipper

Specimen

FlexurePivot

ZipperElectrode

Beam

Pull-inAssist

Applications

• Microfluidics

• Variable Capacitor

• Physics in Gap Experiments

• Alternate Universes!?