Quiz 3 (Lecture 9-11) (No FET)

Question 1

Stimmulation and recording

Answer 1

both use eletronic chips to get data

Question 2

Neuron

Answer 2

acts as controler for the body sending eletrical signals for all essential functions

Question 3

Brain- Machine interface

Answer 3

brain- electrochemcial signals(ionic)
Computer- eletronic signals (electrons)

Question 4

Non invasive neural prosthetics

Answer 4

Limitations- not able to directly interact with CNS
EEG
GSR
fMRI

Question 5

Invasive implantable prosthetics

Answer 5

• techniques- directly targeting singal neurons & collecting local field potentials
• limitations= material biocompatability potential causing gliosis

Question 6

Material biocompatablility 3 measures

Answer 6

A) contruction materials
- Toxicity - smaller dimensions- sharper (reduces tissue response
B) Cell morphology
C) viability

Question 7

Issues with implantation

Answer 7

can cause glial scar response(limit damage by reducing size and increasing sharpness)

Question 8

Living cell Surface Interaction

Answer 8

-many cells must attach to an external surface to avoid apoptosis
- cells ability to stretch and attach have a greater viability then those that are not able to

Question 9

Ionic- Eletronic Interface

Answer 9

• nerve cell is surrounded by eletrically insulating core of lipid
• allows for neuron-semiconductor bioeletric applications to be possible through communication of brain(ionic) and technology (eletronic)

Question 10

Planar Eletrical Core Coat Conductor

Answer 10

• cell adhesion is faciliteted by protein molecules protruding from cell membrane (the proteins stabilize the cleft)
• Cell-Silicon Junction forms the the planar eletrical core conductor

Question 11

Steps of planar eltrical core coat conductor formation

Answer 11

1st step- Neuroeltric interfacing - RECORDING= activity of neuron leads to ionic & displacement currents
STIMULATION= voltage is applied to get displacement current

2nd step Detect TEP-
RECORDING= TEP induced by neuron is probed by the FET
STIMULATION= TEP induced by the chip is probed by the potential acorss the ion chanels in the neronal membrane

Question 12

Coupling of Neurons & Chips

Answer 12

TEP in the cleft facilitates coupling

Question 13

Neuron- silicon integration

Answer 13

NEURONAL NET is used to see how far a signal can travel or for testing cultured neurons
- MICROELECTRONICS- used when there is a damaged piece in between transistor and stimulator

Question 14

silicon neuron junction polarization and stimulation

Answer 14

polarization- allows for direct coupling between electronic and ionic signals

stimulation - involves capacitativly stimulating the neuron

both relate to the cleft region where the current resides between the neuron and the chip

Question 15

Important properties of Nanomaterials

Answer 15

-distribution of electronic levels in optical devices
- High surface area to volume ration
- Size is compatible with biopolymers

Question 16

4 things that characterize nanotech

Answer 16

• size
• ability to synthesize new properties
• ability to image, measure, model
• ability to integrate

Question 17

Metalic Nanoparticals

Answer 17

• improve conductivity and transduction in sensing elements
• can act as catalysts involved in recognition/ transduction processes

Question 18

Carbon fullerene family

Answer 18

sp2 hybridization has better stability ( graphite)
- graphene is made up of benzene- type hexagonal rings

Question 19

3 characteristics of CNTs (n&m)

Answer 19

n=m metallic arm chair
n-m= factor of 3: metallic zigzag or chiral
n-m/= factor of 3 semiconducting zigzag or chiral

Question 20

CNT application in chem sensors

Answer 20

-suitable as molecular wires in electrochemical sensors
- integrated using physcial adsorption, covalent binding or incorperation

Question 21

implications of nanotech in biosensing

Answer 21

nanotech enables us to design smaller, less power hungry, more sensitive systems,

• allows for bionanomaterial hybrids (DNA-NP & DNA-CNT)

Question 22

5 ways to couple

Answer 22

• electrostatic
• streptavidin/biotin
• sulfide bonds - cystein
  - amino acid

Question 23

Discrete V. Integrated

Answer 23

discrete is component by component( arduino/breadboard)
- Integrated is Chips (FET,ISFET)

Question 24

2 substrates of trandsucers

Answer 24

sensor and actuator

Question 25

Sensor

Answer 25

LOD and response time more important than energy conservation

• what is sensed is converted into eletrical signal

Question 26

Actuator

Answer 26

Physical output based on eletrical input ( used in feedback control)
- Dynamic (energy to more dynamic energy) and Bioactuators (eletrical to mechanical)

Question 27

Traditional V. smart sensors

Answer 27

smart sensors have a feedback control integrated that gives them ability to identify and amplify week signals

• traditional sensors have issues with weak signals and noise

Question 28

Active v. Passive sensors

Answer 28

active- is self generating (its own current)(photovoltaic)
passive - modulating (current source is elsewhere)(photoconductive)

Question 29

Sensor amplification

Answer 29

Thevinin(most common) & norton

Question 30

3 golden rules for op-amp

Answer 30

• no current flows into the inputs
• the input voltages are always the same
• the output is able to dive any current required

Question 31

limitaitons of op-amps

Answer 31

white and pink noise
- gain bandwidth product
- clipping output signal for a larger input signal