PROJECT E-MOPED

In this project a Honda Activa with a conventional IC engine was converted into an electric-driven Moped by using a hub motor, controller, swappable battery system and on-board fast charger. It involved various mechanical fabrication processes such as material selection, welding, cutting, grinding, riveting and electrical work such as battery pack assembly, Motor controller wiring and final assembly.

The various processes carried out in converting an Activa into an Electric moped are divided into two sections:

  • Electric Moped Mechanical Workflow
  • Electric Moped Electrical Workflow

ELECTRIC MOPED MECHANICAL WORKFLOW

DISMANTLING OF VEHICLE

The vehicle is dismantled by removing the parts so that the chassis of the vehicle is exposed. The rusted parts are sprayed with WD 40 for easy removal. The parts such as bolt, nut, and screws are kept aside which will be required in reassembling the vehicle.

Dismantled Vehicle

SWINGARM WORK

The existing swing arm of Activa cannot be used as it is mounted with the engine. The calculation regarding hub motor size required wheelbase and height of the vehicle are made. And swing arm of Yamaha FZ Bike was closely matching the requirement. The slotting on the two sides of the swing arm is made to mount the hub motor shaft. The additional tube is arc welded to the Activa frame at the bottom so that the swing arm is bolted to the mainframe.

Slotting of Swingarm and tube welding

SUSPENSION WORK

Usually, Activa comes with single suspension but in our project considering the hub motor size and swing arm profile we used customized two suspensions springs on either side of the frame. The length of the springs is adjusted as per the required vehicle height by welding the extra attachment rings at the end. The extra brackets for mounting the suspensions are fabricated and welded at specific positions on the vehicle chassis and swingarm.

Suspension Mounting

BATTERY AND CHARGER BRACKET WORK

The storage compartment under the seat which is generally used to store the helmet is employed for the placement of the battery pack. The placement of battery and power supply was a challenging task as it was meant to be swappable making it easy for the user. At first, a proper casing is made for the battery pack by using 3mm ABS sheets, which are cut as per design using a laser machine. Then the brackets are made by using a 20X20 mm mild steel angle by cutting at specific lengths. The angles are welded to the vehicle frame at the desired positions.

Angle bracket fabrication

To protect the battery and power supply from water splashes it is covered in all the sides by using 1mm mild steel sheets. The sheets are riveted to the angle by drilling a hole and by using a hand rivet tool. Further gaps are filled by using clear silicone on all the sides to ensure that water doesn’t seep inside the compartment. Belts are provided to the battery and power supply so that they are strapped intact without any vibrations or movements.

ABS Battery Pack Casing
Sheet Metal Work

The final assembly of the battery pack inside the compartment with the necessary wiring and other peripherals such as handle grips is as shown below

Battery Pack Compartment

BODYWORK

The bodywork is done to adjust the battery position without altering vehicle dynamics. The rework on the side stand is made for the required height of the vehicle. Seat lock position is altered and required adjustments are made. Further MSB mounting, throttle, and extra switches are mounted on the vehicle body.

Seat Lock

REAR BRAKE

The rear brake is upgraded from wire to hydraulic disc brake. The brake lever is mounted on the handlebar. The brake caliper is attached to the disc of the hub motor by using a bracket and Allen screws.

Rear Disc Brake

ELECTRIC MOPED ELECTRICAL WORKFLOW

 BATTERY PACK

The battery packs used are enclosed with ABS plastic enclosure and the two batteries are interconnected using Anderson power pole connectors, each battery pack constitutes 180 cells in a 13S 10P configuration.

Battery Pack

Battery cells and configuration:

Cell 18650 Li-ion (NMC)
Nominal Voltage 3.7 V
Rated capacity 2500 mAh
Constant discharge current 5 A
Cell assembly 13S 10P (X2)
Number of cells 260
Battery pack voltage 48 V (nominal) 55 V (peak)

HUB MOTOR

The Hub motor is mounted at the rear end of the vehicle. The motor is equipped with two sets of Hall sensor wires in case one of them gets damaged facilitating ease of replacement. The Hall sensor wires along with the three Phase wires are extended and passed through PVC conduit along the chassis frame till the front end of the vehicle.

Hub motor

Specifications of Hub motor:

Size 12” (304.8mm)
Motor rating 2 KW
Peak power 4.5 KW
Speed 1200 rpm
Top speed of the vehicle 70 kmph at 200 kg gross weight

CHARGER

The charger has a modular set up such that it could be either placed inside the vehicle to facilitate onboard fast charging or it can be removed and taken along with the battery pack to provide fast charging facility through domestic power supply. The fuel tank of the vehicle is removed to place the charger. Mild steel angles and Aluminium sheets are used to make the charger compartment.

Charger Compartment

Specifications of Fast charger:

Charging voltage 55 V
Charging current 15 A
Charging duration ~ 3.5 hrs. (0 – 100%) ~ 2 hr. (20 – 80%)

MOTOR CONTROLLER

The motor controller is placed at the front end of the vehicle, facilitating in better ventilation and thus heat dissipation. This also allows easy access of the controller for wiring and maintenance purposes.

Motor controller

Motor controller rating:

Operating voltage 35 – 60 V
Rated current 80 A
Features 3 Speed modes , Reverse mode, High brake, EBS

MISCELLANEOUS

Wiring:

Appropriate wire gauge was selected after evaluating the magnitude of current flowing through each connection. Hence, higher gauge wire was selected considering the safety factor.

The wire gauges are as follows:

Power wires 6 SWG
Phase wires 11 SWG
Miscellaneous 18 SWG

Ignition:

The ignition wire is connected in series with the vehicle key, SPST switch and a 5A fuse. The other end of this connection is connected to the positive terminal of the controller. The key ensures that the vehicle is turned ON by authorised persons only while the Fuse is used for safety purpose ensuring smooth operation even under repeated switching action.

Speed modes:

There are three speed mode options viz., LOW, MEDIUM & HIGH. These modes are accessed by a SPTT switch mounted on the vehicle dashboard.

Reverse mode:

The reverse mode, in which the motor runs at a lower speed but in the reverse direction can be accessed by a SPST switch mounted on the vehicle dashboard.

In the end, all the required parts have resembled and the vehicle is tested for its performance

Battery and Charger Compartment
Final Vehicle Assembly
Final Vehicle Assembly

Our Story

Covid -19, It was uncalled times for a lot of us here. I run this start-up called FUTURETRON LABS (https://futuretronlabs.in). We work on Electric Vehicle Mobility Solutions, a lot of decisions had to be made during the lock-down period, two of our employees from different districts had to move to their native and I was working out of this place called Workbench Projects Pvt Ltd. Since Workbench Projects is located in the metro station building, they had to shut down the space till the relaxation was lifted, still I was able to access the place once in a while. Then I started to use Dinesh’s place. In the first phases of lock-down I started to use our own custom-built electric bicycle to commute as bicycles were allowed to run on roads during that period. 

Futuretron E-Bike

It was super fun to use the bicycle and also it was a great opportunity for me to test the capacity of the same. I was visiting Servelots/Janastu more often for doing my work during lockdown since it was close to my home.

At Dinesh’s place me along with Anu, used to translate a good talk on Covid-19 by Dr Dave price (Weill Cornell university New York) from English to kannada. One can listen to this here https://public.janastu.org/Covid-19/

The situation of covid19 was shifting rapidly, it was continuing to ravage global communities and as an entrepreneur I was looking at what can be done during these times that will improve our skill sets and enhance company growth, as well as to put our knowledge to use that’s when we developed three products which was very much necessary during this covid-19 emergency. The idea was to make simplistic design of products and make it easily available for the people.

It was very important to clean the often-used devices/equipment’s and disinfect it so we came up with this UV chamber

Ultra violet based Disinfector: Futuretron Uvister :

Then I realised the importance of contact-less sanitizer dispensers. The purpose of contact-less sanitizer dispenser is to help monitor and control the spread of coronavirus by using the same sanitizer bottle from a suspected carrier to a safe and healthy carrier. And we came up with these two products

  • Automatic Contact-less Hand Sanitizer Dispenser :

Foot Operated Contact-less Hand Sanitizer Dispenser:

FUTURETRON FOOT-PEDAL OPERATED HAND SANITIZER DISPENSER

FOOT-PEDAL OPERATED CONTACT-LESS HAND SANITIZER DISPENSER

The COVOD-19 pandemic’s emergence has added yet another level. As the world races to discover vaccines, treatments and cures for the virus, the sanitization, disinfection, decontamination and isolation are also few factors which needs to be used to defend ourselves, and the remedies must be implemented globally.

Hand sanitizers have proven to be one of the better solutions helping us in the fight against the current pandemic situation. Hand sanitizers kill the microorganisms present in one’s hand such as bacteria, virus and other microbes. Although soaps can be used to achieve the same task, finding a washing area and water source makes it difficult to achieve sanitization in all areas also it is not a portable solution. On the other hand, hand sanitizers help us beat all the short comings from conventional hand washing using soap.

The motivation to design the foot pedal operated sanitizer dispenser is to minimize the touch points. Keeping physical contacts away and eliminating the need for multiple people to touch a common point is of utmost priority in current circumstances. Hence the main purpose of contactless sanitizer dispenser is to help monitor and control the spread of virus by using the same sanitizer bottle from a suspected carrier to a safe and healthy carrier.

Foot Pedal Operated Sanitizer Dispenser

It’s a foot operated hand sanitizer dispenser. With this mechanism sanitizer could be used without touching the sanitizer bottle with hands. Whenever user pushes the pedal with foot, the sanitizer is dispensed from the bottle. Sturdy Design, Contactless Dispenser, Movable, Easy to Assemble and Heavy base.

Parameters considered for the design

The sanitizer dispenser must be compatible with different dimensions of sanitizer container. It must be easy to use and dispense the sanitizer in an instant. The build quality must be sturdy and overall operation must be smooth.

Specifications of Foot Pedal Operated Hand Sanitizer Dispenser:

Mode Manual
Type Foot Pedal Press
Material Mild Steel
Dimension W41xL38xH140(cm)
Sanitizer Holder Height and width adjustable

Procedure to use the Foot pedal operated sanitizer dispenser

1] Place the sanitizer bottle in the holder and strap it with the Velcro strips.

2] Adjust height of the dispenser head according to the bottle size.

3] Press the foot pedal to dispense the sanitizer.

Conclusion

The Foot pedal operated sanitizer dispenser solves the problem on two levels. One, it eliminates the need of soap and water for sanitization of hands. Two, it minimizes the touch points and thus achieving effective sanitization.

It is efficient in public places like hospitals, malls, and in companies where large number of people work/gather.

To know more about the product: https://futuretronlabs.in/covid.html

FUTURETRON AUTOMATIC CONTACT-LESS SANITIZER DISPENSER

Automatic Sanitizer Dispenser

The COVOD-19 pandemic’s emergence has added yet another level. As the world races to discover vaccines, treatments and cures for the virus, the sanitization, disinfection, decontamination and isolation are also few factors which needs to be used to defend ourselves, and the remedies must be implemented globally.

Hand sanitizers have proven to be one of the better solutions helping us in the fight against the current pandemic situation. Hand sanitizers kill the microorganisms present in one’s hand such as bacteria, virus and other microbes. Although soaps can be used to achieve the same task, finding a washing area and water source makes it difficult to achieve sanitization in all areas also it is not a portable solution. On the other hand, hand sanitizers help us beat all the short comings from conventional hand washing using soap.

Hence the purpose of contact-less sanitizer dispenser is to help monitor and control the spread of coronavirus by using the same sanitizer bottle from a suspected carrier to a safe and healthy carrier.

Automatic Sanitizer Dispenser

The dispenser is automatic, contactless, easy to install and operate. It will spray hand rubbing sanitizer based on alcohol for hand sanitization. It is spray based and designed to maximize sanitizer consumption.

Parameters considered for the Design

The sanitizer dispenser must be compatible with different dimensions of sanitizer container. It must be easy to use and dispense the sanitizer in an instant. The build quality must be sturdy and overall power consumption should be minimal.

Specifications of Automatic Hand Sanitizer Dispenser

Mode Automatic
Construction Acrylic (Customizations available)
Power 5V1A DC
Spray Discharge 10ml
Sensing range 5cm
Dimension W100xL200xH230(mm)
Weight 500gm

Procedure to use the Automatic sanitizer dispenser

1] Connect the power adaptor and turn on the switch.

2] Place your hand under the dispenser.

3] The sensor can detect the presence of hand up to a range of 5 to 8 cm. The device then dispenses the sanitizer on the palm.

4] Once the person takes away his or her hand, the dispenser automatically turns of the motor and stops the dispensing action.

Note: The sanitizer action is instant. Hence, do not keep your palm for prolonged duration.

Conclusion

The automatic sanitizer dispenser solves the problem on two levels. One, it eliminates the need of soap and water for sanitization of hands. Two, it minimises the touch points and thus achieving effective sanitization.

It can be used in hospitals, corporate buildings, offices, malls etc where large number of people work/gather.

To know more about the product: https://futuretronlabs.in/covid.html

APPLICATIONS OF UV CHAMBER-FUTURETRON UVISTER

HOUSEHOLD PURPOSES
• To disinfect outsourced consumable items like groceries, fruits, vegetables and dairy products.

• To disinfect online delivery packages

• To disinfect the newspapers and postcards • To disinfect vehicle keys and helmets


OFFICE PURPOSES
• To disinfect electronic gadgets like laptop, mouse and mobile phones

• To disinfect the hard cash and files

• To disinfect online food delivery items • To disinfect stationary items like white board marker, duster etc.


MEDICAL PURPOSES
• To disinfect reusable face mask and hand gloves

• To disinfect medical operation hand tools

• To disinfect medicines and syringes


AT BANKS
• To disinfect Hard cash, receipts, files and cheques

• To disinfect ATM cards before or after use


AT SERVICE STATIONS
• To disinfect customer products that came for service or repair.

• To disinfect card payment machines

TO KNOW MORE:

https://www.futuretronlabs.in/covid.html

FUTURETRON UVISTER

The situation of covid19 is shifting rapidly and it continues to ravage global communities, the world is focussed wholly on discovering ways to combat novel coronavirus and it’s important that we protect patients, clients, staffs and families from this situation. It is extremely important to clean the often-used devices/equipment’s and disinfect it. The ability of UV light to inactivate the novel coronavirus has been the subject of research lately. Typically, UVC is used to disinfect the rooms, surfaces and devices. Corona virus can live on certain surfaces such as paper, cardboard, plastic for hours to days. In particular, the virus was found to be active for one day in cardboard, for up to three days in plastic and stainless steel, and for up to four hours in 99% copper. Thus, it’s important to disinfect at regular intervals. UVC light is very effective in inactivating microorganisms such as viruses, bacteria and pathogens.

FUTURETRON UVISTER

Working Principle:

Ultraviolet germicidal irradiation (UVGI) is a decontamination method that uses shorter wavelength UV radiation to inactivate microbes by terminating nucleic acids and disrupting their DNA which makes them powerless to perform certain vital cellular purposes. UVGI is used in a various applications such as food, air purification and water purification. Killing the microorganisms with UV radiation needs the germicidal wavelengths of between 185 to 254 nanometers. Ultra Violet C has wavelength between 100 to 280.

The light is absorbed by the microorganisms’ DNA and RNA, leading to the dimerization of neighboring molecules (particularly thymine). This occurrence in the DNA and RNA of bacteria and virus makes replication impossible for the microorganisms and causes infection.

Note: Prolonged exposure to UVC is not recommended. Hence, maintain a safe distance from the sanitization box during its operation.

Specifications of the UV chamber are as follows

Material Acrylic plastic
Colour White
Wall thickness 5 mm
Dimension 30L x 47W x 30H (cm)
Capacity 36 Litres

Parameters considered for the design

The box must be able to accommodate a wide range of objects that are as small as a key to something as big as a laptop. This box must serve a wide variety of applications and use case scenario. The sanitization process must be quick, easy to use and operation must be hassle free.

Procedure to use the UV Chamber

1] Ensure that the switch is in OFF position.

2] Open the front door, place the object that needs to be sanitized and close the door.

3] Turn on the switch and run the device for 15 to 20 minutes.

4] Once the sanitization process is completed turn off the switch and take out the object. If the object needs to be sanitized at both ends, flip the object and repeat the same procedure.

Safety Precautions

1] Avoid eye and skin exposure.

2] Do not look directly into light.

3] Switch off the device when not in use.

4] Keep the device away from the reach of children.

5] Clean the UV bulbs and chamber once a month.

In practice, the disinfection time would be of 3 to 4 times the theoretical calculation. This is due to various factors such as variation in the UV dose and the actual output of the UV bulb. The chamber has been designed considering various use case scenarios. The design is flexible and could be modified to suit very specific use case as well.

TO KNOW MORE ABOUT THE PRODUCT:

https://www.futuretronlabs.in/covid.html

CHARGING AND DISCHARGING TIME

CHARGING AND DISCHARGING TIME

Time in Hours

At any particular instant the actual current delivered by any cell depends on the load. The Time in hours(H) theoretically would be

Time(H) = Capacity (Ah)/Current(A).

If current is measured in amps and Capacity of a cell/battery in amp-hour, then time is measured in hours for charging and discharging.

For instance,

A 20Ah battery pack delivering 0.5A will last for 40hours

A 20Ah battery pack delivering 1A will last for 20hours

A 20Ah battery pack delivering 2A will last for 10hours

A 20Ah battery pack delivering 20A will last for 1hour

CHARGING TIME AND DISCHARGING TIME

The charging and discharging rate are usually specified by the current.

Example, charged at 10A and discharged at 20A

Charging Time

Charging time is the proportion of charge added to the battery per unit time.

In general scenario charging Time is found by,

Charging Time = Battery Capacity / Applied Current

For instance,

Consider 80Ah battery pack, if the applied current is 20Ah, then the

Charging Time = 80 / 20 = 4 hours.

Discharging Time

Discharging Time= (Battery Capacity x Battery Volt)/Device Watt.

For instance,

Consider a 3.7V 20Ah battery, device watt=20watt

Discharging Time = 20Ah*3.7V/20 = 3.7 hours

Li-ion/ / LiPo batteries with power efficiency of 90%

Then,

Discharging Time = (Battery Capacity x Battery Volt x 0.9)/Device Watt

For instance,

Discharging Time = 20Ah*3.7V*0.9/20 = 3.33 hours

C RATING

C RATING

C rate of the battery is the rate at which the capacity of the battery is charged or discharged to the load. C rating is important in applications which draw high amounts of current.

Maximum Current Draw = Capacity (Ah) x C-Rate

Example, a 3S 2.5Ah 5C LiPo battery pack will draw a maximum safe current of

2500mAh x 5C = 12.5A

Discharging a battery too quickly is not good considering the health of the battery. Due to which internal resistance (IR) will increase than discharging within the battery’s limit.

The battery capacity is generally rated at 1C, which means that the fully charged battery rated at 2Ah must provide 2A for 1 hour. The same battery if rated at 0.5C should provide 1A for 2 hours. Same battery rated at 2C should provide 4A for 30 minutes.

C/10 = C10 = which means C amount of discharge current flowing for 10 hours

C/5 = C5

C/0.5 = C0.5 = 2C

20C = The discharge current the battery is capable of discharging is 20 times C

The higher quality batteries are capable of handling higher charge rates with minimum or no degradation but the lower quality batteries have higher possibility of getting overheat at higher charge rates. It’s always suggested to charge at 1C or follow the recommendations from battery manufacturer regarding high performance and long battery life.

Lets go through some of the mathematical calculations

  • Average Battery Current

IB=C/N

IB = Average battery current

C= Capacity in Ah

N= No of hours of discharge

Example:

For 10Ah of battery and 10hours of discharge

IB=30Ah/10h = 3A

It means that 30Ah of battery is capable of supplying 3Ah of average current to the load up-to 10hours. Though due to losses 30Ah battery can supply 3A average current for less than 10 hours.

  • Continuous Discharge

2500mah battery with 5C rating

Continuous Discharge Amperage = (mAh/1000) x C Rate)

= (2500 /1000) x5=12.5A

  • Run Time for Safe Continuous Discharge

2500mah battery with 5C rating

Run Time = (60min/C-Rate) = (60min/5) = 12min

Therefore, Discharge 25A for 12min

C rating of a battery is very important factor as the energy stored in a battery is dependent on the speed of charging and discharging current.

UV LIGHT APPLICATIONS

APPLICATIONS OF Ultra Violet LIGHT

1] Air Sterilization

UV lights have many applications in industries, households, and healthcare for controlling the odor, environment sterilization and to eliminate harmful volatile organic compounds emitted by factories. In some environments where air quality is crucial for health.

2] Surface Sterilization

In industries like food processing disinfecting the surfaces without the chemical is essential where UV lamps are used. The UV lamp works with the principle of irradiation where ultraviolet light can kill bacteria, viruses, and fungi in a couple of seconds. This will help in extending the shelf life of a food product and preserve the nutritional value. These lights can be installed along with conveyor belts where all incoming foodstuffs get scanned.

3] Water Disinfection

Water disinfection is important to make the water safe for human use by eliminating harmful chemicals like chlorine and environmentally toxic. UV lights are used in the treatment of this water. Other applications like in aquaculture and life science.


4] Arson Investigation

The UV lights are sensitive to the carbon residues from the burning effect on walls, floors, and furniture which helps the fire inspector to scan the fire impacted areas instantly without checking physically.

5] Artwork Inspection

The Ultraviolet lights have a different effect on each material which helps in identifying it. This helps the artwork inspectors to protect themselves from art fraud. It also helps in identifying the repairs in art and other valuable stones like marbles, gems, and even on ivory. It also can detect the age of precious stones.

6] Beauty and Skincare

Ultraviolet light also used in treating skin problems. UV light therapy is usually offered in medical clinics and other licensed professionals. It is used to treat skin problems like Eczema, Vitiligo, Itching, and other problems.

7] Crime Scene Inspection

UV lights are used in forensics to identify the fingerprints, blood, and other body fluids in crime scene investigation. UV lights make these samples glow brightly and it becomes easy to identify.

8] Counterfeit Currency Detection

Ultraviolet light source scanners make different currency denominations glow with a specific color and will show whether bills are genuine or counterfeit.

9] Document Verification

UV light plays an important role in document verification like driver’s licenses, passports, and credit cards. An official document has invisible fluorescent markings that are visible only by using UV light sources.

10] Environmental Investigations

UV lights assist in the environmental investigations by detecting the presence of harmful chemical wastes like hydrocarbons disposed of by petroleum factories. It can be detected on the land and even in water.

11] Gem and Mineral Inspections

Impurities and structural flaws present in the valuable gems stones can be detected by using a UV light. It is used by a gemologist to identify the authentication of gemstones.

12] Non-Destructive testing

UV lamps projected on the surfaces that have been previously treated with a liquid penetration or magnetic particle, which will fluoresce under ultraviolet light, exposing any flaws in the material being examined.

13] Pest Control/ Food and Agriculture

To determine the presence of rodents in the warehouses by scanning urine and hair as it glows blue-white and is easily identified on sacks of food or intermixed with food grains. It also helps in trapping flying insects.

14] Security control

Security professionals need to track visitor’s baggage and items at a public gathering for security concerns. So, these items were more likely inspected with a UV light source which is monitored using screens.

UV Light and How UV radiation Kills Microbes

UV Light: Ultraviolet is an electromagnetic radiation which has a wavelength between 100nm to 400nm. UV radiation is not visible to human eye. Lamps, bulb, crackling fire are some examples of objects that emit UV radiation.

source: http://www.lightlab.com/smarter-uv-light/what-is-uv-light

UV region is divided into three bands

  • Ultra Violet A(315-400nm): UVA possess the lowest energy compared to UVB and UVC. It enters deep into the skin causing various skin damages such as wrinkling of the skin, skin cancer and ageing.
  • Ultra Violet B(280-315nm): UVB has the highest energy compared to UVA and UVC. It affects the outer layer of skin causing sunburn, skin cancer and tans.
  • Ultra Violet C (100-280): Highest energy than UVA and UVB. But it doesn’t reach the earth’s surface, it is absorbed by the ozone layer.
source: http://www.arpansa.gov.au/understanding-radiation/what-is-radiation/non-ionising-radiation/ultaviolet-radiation

According to World Health Organization, as sunlight travels through the atmosphere all UV-C and about 90% of UV-B energy are drawn by ozone, water vapour, oxygen and CO2. UV-A radiation is less affected by the atmosphere compared to other two radiation. Therefore, the UV radiation touching the earth’s surface is mainly composed of UV-A with a small amount UV-B factor.

Ultraviolet germicidal irradiation (UVGI) is a decontamination method that uses shorter wavelength UV radiation to inactivate microbes by terminating nucleic acids and disrupting their DNA which makes them powerless to perform certain vital cellular purposes. UVGI is used in a various applications such as food, air purification and water purification.

Killing the microorganisms with UV radiation needs the germicidal wavelengths of between 185 to 254 nanometers. UVC light on earth’s surface is very weak, since the ozone layer blocks it. UVGI devices produces sufficient UVC radiation in air or water systems which breaks apart the derm DNA to make them inactive in environments to microbes such as bacteriaviruses other pathogens. UVC has the strongest germicidal outcome which is very effective in killing or inactivating bacteria, viruses and other pathogens.

A group of single celled microbes which reproduce through the process of cell division are called Bacteria. This single cell feature of bacteria makes it decontaminated by UV radiation as the major form of reproduction in bacteria happens through the process of cell division. Any form of modification in the cell structure of the bacteria can affect the method of cell division.

HOW UV RADIATION KILLS CELLS

DNA is made up of two complementary strands that are twisted together into a double helix structure. This structure is made up of four nucleotides Adenine(A), Thymine(T), Guanine(G) and Cytosine(C). UV radiation kills the cells or the process of cell division by damaging their DNA. When UV light falls on bacteria it initiates a reaction between two thymine molecules, it is one of the bases that form DNA. The subsequent thymine dimer produced is very stable but fixing this DNA damage is by removing the two thymine bases and replacing with new nucleotides, which is not an efficient method.

[Dimers: It’s a chemical compound made up of two identical subunits or monomers]

Extensive exposure to UV radiation results in the formation of more thymine dimers in the DNA which produces an incorrect repair or missing dimer. If the process of cell division is interrupted due to an incorrect repair, missing dimer or any damage then the cell cannot do its normal functions. At this point the cell will die or directs the cell to apoptosis.

CALCULATION OF EXPOSURE TIME REQUIRED FOR DISINFECTION:

The unit of brightness is typically expressed in microwatt per centimeter (μW/cm2) and the exposure time employed for UV sterilization is directly proportional to UV dosage. The mathematical calculations for the same are as shown below.