Comb Drive Uses in Blood Pressure

/prep7

/title Comb drive resonator with FLUID139 Couette damping

! DRIVE COMB

! |

! |

! CRAB LEG SPRING --- CENTRAL MASS --- CRAB LEG SPRING

! |

! |

! PICK-UP COMB

! Reference:

! "Microelectromechanical Filters for Signal Processing",

! Lin, L., Howe, R.T., J. Microelectromechanical Systems,

! VOL 7, No. 3, Sept 1998

! beam parameters (uMKS units)

E = 190e3 !Young modulus

d = 2.33e-15 ! density

hb = 2 ! beam thickness

wb = 2 ! beam width

Lb = 100 ! beam length

k = 5.699 ! mechanical stiffness

! comb parameter

n= 9 ! number of finger

np=n*2 ! number of finger pairs

x0= 10 ! initial finger overlap

L0= 26 ! finger length (stator comb)

L=20 ! finger length (moving comb)

gi= L0-x0 ! initial gap

w= 4 ! finger width

h= hb ! finger thickness

gp=3 ! finger gap (lateral)

g= 3 ! comb gap (vertical)

Mr = 1.96563e-11 ! mass

! Lateral gap area

areal=np*h*x0

! Vertical gap area

areav=n*w*x0

! Stroke vs. Capacitance data

x1 = 14

cx1 = 0.97857e-2

x2 = 15

cx2 = 0.96669e-2

x3 = 16

cx3 = 0.95445e-2

x4 = 17

cx4 = 0.94185e-2

x5 = 18

cx5 = 0.93384e-2

! Voltage conditions

Vi = 40 ! input dc bias

Vo = 60 ! output dc bias

Vac = 10 ! input ac bias

! Damping parmeters

nu=18.3e-12 ! dynamic viscosity

po=0.1 ! reference pressure

dens=1.17e-18 ! density

fc=nu/(2*3.14159*dens*(g**2)) ! cutoff frequency

daduv=w*n

...