Biosensors

This blog page can be used for a last minute revision on the topic of 'Biosensors' from the material science course.                         

                                                  Biosensors 

Components of Biosensors

- Biological recognition element 

- Transducer

- Actuator

Functions of the components

Biological recognition element - To sense the response

Transducer - To generate electrical response
Actuator - Measurement and Analysis

How does the biosensor work ?

Analyte - It is what you detect which could be a chemical or a biological substance .

Biorecognition element - The biological species which provides specific recognition or detection of                                               the analyte.

Transducer - It helps to convert bio recognition event into a measurable signal .

- Only a specific types of molecules will be recognized by the bio recognition element. Thus triggering the bio-recognition event . Then the transducer will  convert the bio recognition event into a measurable signal.

How to access the performance of the biosensor

-Selectivity of particular analyte or particular group of analyte

-Sensitivity of the biosensor

- Linear Range

- Limit of Detection

-Reproducibility

- Time

- Multiplexing ability

- Sensitivity to pH and temperature

- Portability

- In vivo application

-Ease of use

Types of Industries that requires biosensors

- Pathogen detection

- Counter- Bio-terrorism

- Medical Diagnostics

- Environmental monitering

The future of cars

Nanotechnology importance in the automotive industry

There will be many advances for the cars in the future and nanotechnology will be the sole reason to that . The advances that you will see in the future will be mind blowing as Nanotechnology will be enhancing every aspects of a car significantly.Applications range from the already existing ' Paint quality ','Fuel cells ', 'Batteries ', 'Wear-resistant tires ', 'Lighter but stronger materials', 'Ultra-thin anti-glare layers for windows and mirrors' transforming to the futuristic bodywork which consist of fully self-repairing paint, switchable colors and shape-shifting skin.

Advantages of Nanotechnology on Cars

- Lighter but stronger materials will be used which is for better fuel consumption and increased safety

- There will be improved engine efficiency and fuel consumption for gasoline-powered cars 

- There will be reduced environmental impact from hydrogen and fuel cell-powered cars

-  There will be enhanced and miniaturized electronic systems

- There will be better economies such as longer service life ,  lower component failure rate and also  smart materials for self-repair .

Source: Hessian Ministry of Economy, Transport, Urban and Regional Development

Applications of Nanotechnology in vehicles 

 - In present-day cars, a huge amount of percentage of the vehicle’s weight comes from the weight of the engine and the transmission system of the vehicle.  With the arrival of the alloys, the engines were made lighter in a way  but not enough to make the engines fuel-efficient. The remedy to this problem came in a form of nanotechnology  . With nanotechnology, engines and parts of the vehicle  were being made a lot lighter and remove the need of consuming more fuel in order to power the vehicle forward.

- Apart from being made lighter , the chassis and engines were being made more durable allowing to hold out against the daily workload on the road.

- The another example of  nanotechnology advancements is the production of paint that is comprised in micro volumes. The plan is that to create a surface which instantly heals itself whenever it is scratched or tainted with some foreign mark. This process enables the paint to release the nano paint particles which will instantly  spread to cover up the scratched area. Later , at some point of time , you will hardly see the scratched area.

- The other advancement of nanotechnology will be the mirrors and side panels which are made up of nano particles . It helps to filter the smoke and other pollutants in the atmosphere and also enable the radio and phone signals to enter the cars so that the people in the vehicle will not be made unaware to the surroundings outside the vehicle. 

References 

http://www.dummies.com/education/science/nanotechnology/nanotechnology-makes-cars-shinier-safer-more-fuel-efficient/

http://www.nanowerk.com/spotlight/spotid=18972.php

http://nanogloss.com/nanotechnology/nanotechnology-in-cars/#axzz4YeUHlNtU

Biomaterials and it's applications

 Biomaterials

- Bio material is a material used in a medical device that is non-viable and interacts with the biological systems . The bio materials field has seen steady growth over  fifty years of existence  and utilises ideas from medicine, biology, chemistry, materials science and engineering.

- For the most part , bio materials are used for medical applications. Not only that , bio materials are used  to grow cells in culture in order to assay for blood proteins in the clinical laboratory, in processing bio molecules in biotechnology and for investigational cell-silicon known as "Bio Chips ".

- What makes these application common among each other is that  the interaction between biological systems and synthetic or modified natural materials. Bio materials are seldom being used on their own but then , they are often integrated into many devices or implants.

Common bio material medical devices

Area of problem	Bio material applications
Assisting in healing	Sutures , Bone plates and screws
Improve function	Cardiac pacemaker , intraocular lens
Aid to diagnosis	Probes , Catheters
Replacement of diseased or damaged part	Artificial hip joint , Kidney dialysis machine

Requirements for a bio materials  

-  Bio compatible

- Non Toxic

- Non Viable

- Sterility

- Mechanical and Performance Requirement

Here are some examples of various types of biomaterials

Metallic Biomaterials

The 'Vanadium Steel' is the first metal alloy that was being produced specifically for human usage and to manufacture bone fracture plates and screws . Various metals such as iron (Fe), chromium (Cr), cobalt (Co), nickel (Ni), titanium (Ti), molybdenum (Mo), and tungsten (W) that were used to create alloys for manufacturing implants can only be tolerated by the body in small amounts. The bio-compatibility of the metallic implant is taken into consideration as these implants can corrode in an in vivo environment . The outcome of  the corrosion are that the implant material perse will be disintegrate, weakening the implant and the deleterious effect of corrosion products on the surrounding tissues and organs .

Ceramic Biomaterials

The essential properties of bio-materials are should be non-toxic, non-carcinogenic, bio-compatible and  bio functional for its lifetime in the host. Usually ceramics are hard . Ceramics are being used  in implant fabrications can be categorized  as non-absorbable which is unreactive, bioactive or surface reactive which is semi reactive  and biodegradable or reabsorbable which is not reactive. Alumina, zirconia, silicone nitrides, and carbons are some examples of unreactive bioceramics. Certain glass ceramics and dense hydroxyapatites are semi reactive and the calcium phosphates and calcium aluminates are reabsorbable ceramics. 

Polymeric Biomaterials

The synthetic polymeric bio materials are generally used in medical disposable supplies, prosthetic materials, polymeric drug delivery systems,tissue engineered products and orthodoses like those which consist of metal and ceramics substituents. The main advantages of the polymeric bio materials are able to manufacture to produce various types of  shapes such as latex and film effortlessly, secondary processability, reasonable amount of cost and having desired mechanical and physical properties. The essential properties of polymeric bio materials are same as other bio materials which are  bio-compatibility, sterilizability, it's mechanical and physical properties.

In conclusion , you should take into consideration that which biomaterials belong to which category as this will prevent from any negative concequences to our human body . The main priorities for the biomaterials are biocompactability , bioinert , bioactive or surface reactivity , biodegradable , reasonable cost and many more. The biomaterials classification is really essential in medical industries .

References

file:///C:/Users/admin/Downloads/Classification_of_Biomaterials_used_in_Medicine.pdf

https://www.uweb.engr.washington.edu/research/tutorials/introbiomat.html

https://mse.osu.edu/research/biomaterials

Nanotechnology's impact in medicine field

Nanotechnology's impact in medicine field

Nanotechnology plays a major role in field of medicine . The usage of nanotechnology provides interesting possibilities . Well , Nanotechnology in medicine field the applications of nano particles that are currently under development. Not only that, a longer range research that involves the usage of manufactured nano-robots to make repairs at the cellular level . The use of nanotechnology could change radically the way we detect and treat the damage in our body and the disease the future. There are many applications of nanotechnology in the medicine field . The operation at nano scale allows
exploitation of physical properties different from those observed at micro scale such as volume/surface ratio. Here are some of the various examples that are the stated below here.

Medical Application : Drug Delivery

This application is being developed in the medicine field which uses nano particles to deliver drug , heat , light and other substances . The particles are engineered in order for them to be attracted to the diseased cells. which provides a  direct treatment of those cells. Not only that ,  this technique also helps decreases the  damage to healthy cells in the body and allows it for earlier detection of disease.

Medical Application : Nano medicine diagnostics

For the past few decades , imaging turned out to be an essential tool in the diagnosis of disease. The advances of the magnetic resonance and computer tomography are extraordinary , but not only that nanotechnology assures sensitive and accurate tools for in vitro and in vivo diagnostics that are far ahead of today’s state-of-the-art equipment. Well ,  the utmost target is to allow the physicians to identify the disease as soon as possible. The Nanotechnology field  is believed to make diagnosis possible at the cellular and even the sub-cellular level.

The Quantum dots had taken the step from pure demonstration experiments to real applications in imaging. In recent years, the scientists have discovered that these nano crystals allows researchers to study and comprehend cell processes at the level of a single molecule. This drastically enhance the diagnosis and treatment of cancers.

The fluorescent semiconductor quantum dots prove to be extremely beneficial for medical applications, such as high-resolution cellular imaging. Whereas , the quantum dots  could change medicine radically but the drawback is that most of it are toxic . Well , recently studies has shown protective coatings for quantum dots may eliminate toxicity.

References

http://www.understandingnano.com/medicine.html

http://www.nanowerk.com/nanotechnology-in-medicine.php

How Nanotechnology can save the environment ?

How Nanotechnology can save the environment ?

Nanotechnology plays a crucial  role in today's world. It also plays a massive role in saving the environment by saving raw materials , energy , water. Not only that , it reduces the greenhouse gases and hazardous wastes. Nano materials are environment-friendly products as they do have unique physical and chemical properties .

The Benefits of Nanotechnology to the environment

There are various benefits of nanotechnology can save the environment . The benefits are the it helps to increase the useful life due to the increased amount of durability of the material against the mechanical strength . The nanotechnology - based dirt and the water resistant coating helps to decrease the cleaning efforts . Nano materials also helps to advance the energy efficiency of the building .The other benefits , the nano particles are being added to decrease the weight and save energy from the transport.

There are also other examples too . In the chemical industry , the nano materials are being applied according to their special catalytic properties which is to boost the energy and the resource efficiency . Not only that the nano materials also helps to take over from the environmentally problematic chemicals in certain fields . The nano technologically optimized products are at the development phase which will help significantly for the protection of the climate and also resolving other energy problems in future.


Nano materials are also useful in cleaning up the air , water and ground pollutants . Well , special filters and processes are being used to that makes the nano particles to bind with the pollutants are the basis for these new developments as this might be essential in cleaning up the contaminated water. For the air pollutants ,  the face mask made form nano materials will help to degrade and absorb the viruses present in the atmosphere.

The titanium oxide nano particles are well known for breaking down dirt when the sun shines on the nano particles .  The layers of the titanium oxide nano particles are being placed on the glass of the windows as they are self-cleaning . In terms of reducing the emissions form the car fuels that increases the efficiency of the combustion and gases are being broken down into lesser harmful compounds .The Nano products will use the heat and then convert it to energy.

Stronger and lighter materials are being created by nano materials . A well known examples are the carbon nano tubes. They make a massive positive  environmental impact as by making the air planes lighter making it last longer to decrease the amount of material in landfills and recycle.

Nanotechnology Applications that are beneficial to the environment

Nanomaterials for radioactive waste clean-up in water


For the radioactive waste clean-up , the scientist are working on nanotechnology solution , mainly using the nano fibres the absorbents to remove the radioactive ions from the water. Researchers have also indicated that the titanate nano tubes and nano fibres unique structural properties lead them to becoming a superior materials for removing the radioactive cesium and iodine ions in the water.

For Carbon Dioxide capture

Before the carbon dioxide could be stored in the carbon dioxide capture and storage schemes , it needs to separated from the other waste gases that results from combustion or industrial process . The currents that are being used are expensive and require the usage of chemicals . To resolve this issue , nanotechnology techniques are being implemented to fabricate the nanoscale thin membranes which result to a new membrane technology to change that.

References

http://www.nanowerk.com/nanotechnology-and-the-environment.php

http://www.nanoandme.org/nano-products/environment/

Failure Analysis

This blog page can be used for a last minute revision on the topic of ' Failure Analysis' from the material science course.

Failure Analysis

What is failure ?

- It is a machine or a component that is unable to function as intended. Types of failures are distortion , fracture and wear.

What is failure analysis ?

- It is an examination of the failed component and of the failed situation which will help us to determine the causes of the failure.

Types of failure and it's description

Fracture - It is the separation of  an object or material into two or more pieces under the action of stress .

Wear - Wear is a failure where the fracture toughness causes the material to degrade . Undesirable removal of the materials from the contacting surfaces .

Fatigue - Material fatigue is the weakening of the materials due to repeatedly applied loads . The progressive and the localised strutural damage happens when a material undergoes cyclic loading . The maximum stress values are less than the ultimate tensile stress limit .

Corrosion -  It is the gradual destruction of materials due to the chemical reaction with it's environment.

Distortion - Undesirable alteration in shape of the material

Creep - It is the tendency of a material to move slowly or to be deformed permanently due to mechanical stresses. 

Failure Analysis process

Step 1 : Background review

Step 2 : Catalogue Evidence

Step 3 : Examine and Test Evidence

Step 4 : Analyse all Data

Step 5 : Conclusions and Recommendation

Macroscopic Examination

- The macroscopic examination are being conducted with an  unaided eye , magnifying glass or microscope at lower magnification . The magnification ranges from 1 to 50 times .

Microscopic Examination

- The microscopic examination are conducted at higher magnifications . The magnification ranges up to 200000 times . This examination is essential for providing micro structure feature of failed surface and also to provide the evidences of the failed mechanism,

Non- Destructive Testing

- It is a test method that allows physical properties of the failue mechanism to be examined without taking the samples out of service. The test must not destroy the material taht is being examined or damage it's future serviceability .

- Examples are radiographic and ultrasonic .

Destructive Testing

- This test involves removing a metal component form service and sectioning the component for analysis. The purpose for this test is to find out whether the design met the required standards with the process or not and also find out the process defect .

- Examples are tensile testing , impact testing

Nano Materials

This blog page can be used for a last minute revision on the topic of 'Nano materials' from the material science course.

Nano materials

- The scientific notation for the prefix nano is 1 x 10^-9 

- It is equal to the one-billionth of a meter .

- Nanomaterials are very small in size , having at least one  dimension of 100 nm and below .

 Examples of objects on a nanometer scale 

- Virus ( 50nm)

- DNA (2.5 nm )

Properties of Nano materials

- Materials at the nanoscale have unusual physical , chemical and biological properties.

- Nanomaterials are stronger and have different magnetic properties compared to the  other various  forms , sizes or the same material.

- Nanomaterials are really good conductors of heat and electricity .

- Nanomaterials are more chemically reactive  , reflect light better and also the colour varies when their size or the structure is being modified.

What is so great about Nanoscale ?

Surface effects

- Nanomaterials have a larger surface area compared to other similar masses of large scale materials.

- 1cm³  of the cubic nanoparticles will have total-surface area one third larger than a football field. When the surface area of the material increases, a larger amount of material can come in contact with the surrounding materials . This leads to affecting the reactivity of the material.

Surface-area-to-volume (SAV) ratio

'a' represents each side of cube length 

- Surface Area of the Cube of length a = 6a²

- Volume of the cube = a³

- Thus the SAV ratio will be 6/a

 - The SAV ratio of a cube increases  when the dimensions of the cube increases .

- The S.I Unit for SAV ratio is m^-1

- There will be a higher SAV ratio under the nanoscale when compared to the corresponding ratio at the macroscale.

- A heavy material that is being subdivided into a group of individual nanomaterials , the total will remain the same but the total surface area will be largely increased .

Colour

- The changes in colour are due to the various manner in which the photons interacts with the nanomaterials when compared to other materials.

Reactivity

Can drinks made up of aluminium

-  Aluminium is being used to make can drinks.

-  At the nanoscale , the aluminium particles are very reactive and thus will explode.

- When the surface area of the aluminium increases , the size of the aluminiun will decrease . A larger    amount of aluminum will come in contact with surrounding materials  , hence making the material      very reactive.

Electrical Conductivity

Carbon nanotubes

- Carbon nanotubes possesses a high electrical conductivity .

- The reason for the possession of high electrical conductivity is because of the unique cylindrical nanostructure of the carbon nanotubes.

Quantum Effects

What are quantum effects ?

- When the material is at the nanoscale , it's properties will vary drastically . These changes are known as quantum effects.

- When the particle size is at nanoscale range , it's properties such as colour , mechanical strength , electrical conductivity and reactivity  change as a function of the size of the particle.

- Scientists can make small adjustments to a nano material's property of interest such as colour , mechanical strength by changing the size of the material.

Applications of Nanomaterials

-  Zinc oxide nanoparticles dispersed in industrial coatings in order to protect wood, textiles from exposure to UV rays
- Miniaturised electrodes for biosensors