Download Automation & Robotics Research Institute (ARRI)

F.L. Lewis, Assoc. Director for Research
Moncrief-O’Donnell Endowed Chair
Head, Controls, Sensors, MEMS Group
Automation & Robotics Research Institute (ARRI)
The University of Texas at Arlington
Bruno Borovic
MEMS Modeling and Control
With Ai Qun Liu, NTU Singapore
T
Thermal Model
Rttot T 
T s 

qs  1  sCRttot T 
Rtcd
Ct
Rtcv
Mechanical Model
Rtr
q
d 2x
dx
m 2  cm x   k m x   f t 
dt
dt
Trm
Electrical Model
Optical Model
1/ 2
I s  
C
L
R
sCe
V s 
s 2 LCe  sCe Re T   1
 t 2  s2 
2
U (t , s) 
exp 
2 
w0 2
 w0 
Z(s)=R+sL+1/sC
Experiment
160
140
100
ttot
[K/W]
120
R
FEA
80
60
40
1
2
3
4
5
V[V]
6
7
8
9
MEMS Power Generation
Permanent
magnet
S
Vibrating body
with the coil
N
MEMS
Chip
N
S
Ferromagnetic
material
Non- ferromagnetic
material
Vibration-driven E-Mag generator
Fab Layout of Coils with
Folded Beam Suspension
Pressure Sensors for Pulmonary Ventilator Control
Load-deflection relation for square membrane
t
Et 3  Et 3
P  C1 4 w0   C2 4  C3 2 w0
a
a
a 

Optical Pressure Sensor
FEA of membrane deflection
s max 
Fig. 2. Relation between intensity loss and beam offset.
0
-0.5
intensity loss (db)
Maximum membrane slope occurs at
(x,y)= (a,a/2), (a,3a/2), (a/2,a), (3a/2,a).
maximum slope is
w0
2a

  Pa 4 


2  C1 Et 
-1
-1.5
-2
-2.5
-3
0
0.05
0.1
0.15
0.2
0.25
0.3
0.35
relative beam offset theta/theta0
0.4
0.45
0.5
Fiber intensity loss vs. beam offset
with Wendell McCulley- InterMEMS, Inc.
MEMS process Fab layout
1/ 3
Testing and Calibration of Optical Pressure Sensors
Array of membranes with
different dimensions
MicroFAB, Inc. fiberoptics
Optical micro-lenses
David Wallace
Optical Pressure
Sensor Calibration
Facility
Flow Sensors for Pulmonary Ventilator Control
Au
mirror

w
Out of 2Dplane assembly
Flow V
D
Thermal Actuator
movement

Self-assembled
Fixed support
stanchions
L
Linear slide
movement
k
Self-Assembly Sequence
Si
springs
Optical
fiber
Drag Force
FD  12 V 2C D A
Hinges
Optical Flow Sensor
FEA
For a wide range of Reynolds numbers, CD= 1.28
R
Reynolds Number
Vd

Drag torque about the hinged bottom
  2 L2   2 

 D  C D w V (r )r dr  C D wV0 

0
2 
 2.6
1
2
L
2
2
1
2
Where a Cermak flow velocity profile is assumed
Steady-state tilt angle is
  12
Surface Micromachined Design
C D wV0 2   2
k


2
.
6

L2   2 

2 
Flow Sensor based on von Karman Vortices
No moving parts!
x
flow
V
z
Optical fiber
d
w
Bluff
Body
t
Vibrating
beam
MicroFluidics for VLSI Chip Cooling
Number of transistors on a chip is now limited by heat dissipation.
Fabricate micro-channels on the back of the chip for cooling.
With Dereje Agonafer, Director
UTA Packaging Center
Intellisuite simulation showing dry (RIE) etching of 110 Si to get Micro Channels.
Channels are more than 100 microns high (ARRI).
Biochemical Monitoring
•
•
MEMS sensors for biochemical species including
anthrax, nerve gases, NOx, organophosphorus
Wireless Sensor Networks for remote site biochemical
monitoring
1. BCW Detectors
Molecular Recognition and Supramolecular Chemistry - D. Rudkevich
In miniaturized supramolecular devices –
sensors, surfaces, and membranes communication between the analyte-guests and
their receptors on a molecular level is
transformed to measurable macroscopic
effects
VISUAL RESPONSE
GAS
SUPPORT
GAS
SUPPORT
RECEPTORS
SENSORS
calixarenes as unique, specific
NO2-sensing species
these interactions are reversible,
unique, and specific
SENSING MATERIALS
1. BCW Detectors
Proteins (enzymes and antibodies) and aptamers as BCW
sensors – R. Gracy, UNT Health Science Center
Functional protein microarrays
bind specific capture molecules to
solid matrix materials
Immunoassay for oxidized Fibrinogen
isoforms as biomarkers for Alzheimer’s
disease
Oligonucleotide aptamers
bind selected molecules
Anti-ricin Aptamer as potential Biosensor for ricin
2. Thin Films for BCW Detector Support
template-directed growth of
thin films and composites.
Structured chemically-active
nanosphere thin films- K. Rajeshwar
Deposit
chemically
active agent
and dissolve
nanospheres
PS ball
Electrostatically self-assembled polystyrene
nanospheres
To improve sensitivity to challenge
agents down to ppb, it is necessary to
improve charge separation to prevent
recombination of electron/hole
photogenerated charges.
B Si
TiO2 or CdS
,
IT
Metal or
Semiconductor
Site-proximity mechanism in a Ni/TiO2 composite
film illustrating the complementary roles of the Ni
and TiO2 components.
3. MEMS Platforms for BCW Detection Agents
Interdigitated Finger Gate Electrode FET
Uses induced resistivity changes
3x3 IGEFET sensor
micro-array – E. Kolesar
Microcantilever MEMS
sensor array- Kolesar
Uses induced mass changes
DSP and C&C User
Interface for
wireless networksLewis
Neural network classification for unique signatures
Microassembly Station
Camera
Resolution: NTSC
Vertical
Focusing
Stage
MP-285
XYZ degree of freedom
Motorized probe
Resolution: 40 nm
IMAGE AQUISITION
CARD
Analog / Digital Input
- output CARD
MOTION
CONTROLLERS
LabView
&
Windows CVI
Rotational stage
Resolution: 0.01 deg
Table
XY Stage mounted on
rotational stage
Resolution: 3 m, 0.01 deg
Microscope
RS-232
Camera
Resolution: NTSC
Vertical
Focusing
Stage
MP-285
XYZ degree of freedom
Motorized probe
Resolution: 40 nm
Micro Manipulator
IMAGE AQUISITION
CARD
Analog / Digital Input
- output CARD
MOTION
CONTROLLERS
LabView
&
Windows CVI
Rotational stage
Resolution: 0.01 deg
Table
XY Stage mounted on
rotational stage
Resolution: 3 m, 0.01 deg
Microscope
RS-232
MP-285
Probe Controller
Manual Control
Automatic Probe MP-285
NI Hardware
Camera
Resolution: NTSC
Vertical
Focusing
Stage
MP-285
XYZ degree of freedom
Motorized probe
Resolution: 40 nm
IMAGE AQUISITION
CARD
* Already in use
Analog / Digital Input
- output CARD
MOTION
CONTROLLERS
LabView
&
Windows CVI
**Ideally, PXI system + SCXI signal conditioning
Rotational stage
Resolution: 0.01 deg
Table
XY Stage mounted on
rotational stage
Resolution: 3 m, 0.01 deg
Microscope
RS-232
• NI 1411 IMAQ card (Image Acquisition)*
• NI6711 PCI card (Data Aquisition)*
• NI 485/8 Serial Port Card (serial com. with controlller)
• SCXI – Signal conditioning (thermocouple,…etc.)
Vision & Automatic Probe Front Panel
IMAGE AQUISITION
CARD
Analog / Digital Input
- output CARD
MOTION
CONTROLLERS
LabView
&
Windows CVI
RS-232
Vision Feedback
Vision
info
Stored map
Map
From
MEMS-Pro
3D info
Feature-based
Localization
With 3D info
Based or pre-programmed behaviours
OpenGL LabWindows /CVI
IMAGE AQUISITION
CARD
Analog / Digital Input
- output CARD
MOTION
CONTROLLERS
LabView
&
Windows CVI
RS-232
MEMS Packaging
with Wendell McCulley
Dereje Agonafer
Packaging for MEMS Pressure Sensor- W. McCulley
Piet
Mondrian
Pantographs for Position & Force Scaling