A design concept for nanowire based sensor and arrays is described.

1. NANO WIRE BASED SENSOR
ARRAY
SUBMITTED BY,
K.shobica

2. content
 Abstract
 Introduction
 Fabrication
 Nanowire sensor
 Biochemical sensor
 Gas sensor
 PH sensor
 Summary
 Conclusion

3. ABSTRACT
 A design concept for nanowire based sensor and
arrays is described.
 The fabrication technique involves electro
deposition to directly grow nanowire between thin
film contact electrodes.
 To prove our concept,we have electro deposited 1-
um diameter pd single wire and small arrays.
 To demonstrate nanowire sensors, we have
electrochemically grown metal(pd,au,pt).

4. INTRODUCTION
 There is a great deal of interest in nano structure
for potential application in such area as
electronics,biochemical,materials and medicine.
 One-dimensional structure materials such as
nano wire and carbon nanotube.
 The technique involves electro deposition to
directly grow nanowires between patterned thin
film contact electrodes,eliminating expensive and
tedious post-growth device assembly.

5. FABRICATION
 The processes used in this work,including
cleaning,dry etching,low pressure chemical
vapour deposition ,lithography,dielectric
deposition,e-beam lithography,metallization and
electro chemical deposition are standard
semiconductor device fabrication techniques.
 When a electrical potential is applied between
the electrodes,a wire grows from cathode to
anode through the channel.

6. FABRICATION
 Electro deposited with connected wire


7. fabrication
 Two electrode configuration:

8. NANOWIRE SENSOR
 While the ultimate goal is to fabricate
individually addressable nanowire sensor
array,single sensor based on nanowire bundles
are also being investigated.
 This approach allows development of nanowire
surface modification techniques and selectivity
in parallel with the development of the nanowire
array fabrication.

9. BIOCHEMICAL SENSOR
 Biosensors can be created by electronically
coupling the appropriate redox enzymes to a
metal electrode modified with a self-assembled
monolayer to facilitate enzyme immobilization
and to reject interfering species.

10. GAS SENSOR
 Nano wire based gas sensors can potentially
exhibit a fast response with a substantially
higher sensitivity and selectivity than existing
sensor.
 The basic principle behind nano wire gas
sensor is the detection of small concentrations
by measuring changes in electrical conductance
in nanowire produced by the adsorption of the
chemical species by phase change in nano
wire.

11. PH SENSOR
 The concentration of the H30+ is a critical
parameter to be measured for monitoring the
condition of aqueous biological species ,or for
predicting the path of chemical reaction.

12. summary