ARCTek3

Cellulose paper based sensors

Jin-Woo Han & M. MeyyappanOct. 16 2012

ARCTek3

Advantages of paper based sensors

• Sensors fabricated on a paper gas sensor, chemical detector, bio sensor, and strain gauge

• Features Flexible, bendable, foldable Bio-degradable: green technology Robust in cryo-temperatures role-to-role printing or ink-jet printing process Extremely cheaper than solid-state sensors: disposable

• NASA Applications Biomedical sensor, single-time use sensor Detection of structural defects and cracks, structural health monitoring

Commercial:Intelligent packaging, advertising banner, newspaper.

ARCTek3

-1 0 1-2

-1

0

1

2

CNT on paper

50%50%

Cu

rren

t (µ

A)

Voltage (V)

RH=10%

Bare paper

Example: humidity/water vapor sensing

0 50 100 150 200 250

1.0

1.2

1.4

1.6

1.8

60%

Co

nd

uct

ance

(µS

)

Time (sec)

RH=10%

-40 0 40 80 120 160 2000.8

1.0

1.2

1.4

1.6

1.8

60%

40%

30%

10%

Co

nd

uct

ance

(µS

)

Time (min)

RH=

The chemical reaction between H2O and CNT surface changes the conductivity of CNT according to the relative humidity.

ARCTek3

Example: displacement(strain) gauge

After stabilization, the connectivity with neighboring CNTs changes the conductivity of CNT according to the bending curvature.

Tensile stress-less conductive

Compressive stress-more conductive

CNT Paper

Flat state

0 2 4 6 8 100.2

0.4

0.6

0.8

1.0

1.2

Co

nd

uct

anc

e (µ

S)

Frequency (#)100 105 110

20

40

60

80

100

120

Co

nd

uct

an

ce

(n

S)

Frequency (#)

Early stage Steady stage