piezoelectric transducer (ultrasonic fogger) for Fogponics

[fogponicsguy]

Hello all never really done this before but here goes nothing, I am looking talk to an engineer (I have no idea what kind of engineer I am looking for) to help design piezoelectric transducer (ultrasonic fogger) for Fogponics. Fogponics is used to grow herbs/vegetables/fruits and is a form of Aeroponics that uses a piezoelectric transducer (ultrasonic foggers) to atomize the water into particles that are micrometres in size which is the size roots absorb water at.

Water droplet size is crucial, too large a water droplet means less oxygen is available to the root system too fine a water droplet such as those generated by the ultrasonic foggers (5-15 micrometres) produce excessive root hair without developing a lateral root system for sustained growth. High Pressure Areoponics makes mist of 5-50 micrometres micro-droplets which are necessary for long-term growing.

I have done extensive research on the pros and cons of fogponics mostly using https://ganjadigger.com which searches ICmag, Roll It Up, Grass City, THC Farmer, Cannabis, Cannabis Culture, Open Grow, Gardens Cure, 420 Magazine. Why these sites you might ask because they are really the only ones with people trying out this type of system and pushing it forward. At best the information on the site is fragmented with arguments for and against fogponics, I want to compile all the data I can mine from them and put it into a clear and concise all-encompassing manual for growing using fogponics and give it back to the communities because I believe sharing/open sourcing is the best way to innovation. These are my findings so far for Fogponics

Pros for Fogponics:
-Uses less water and nutrients, 70% less then hydroponics which already uses 70% less then traditional farming
-High Yield
-Growth speed on roots is amazing, large mass and very fuzzy; growth of stems is very quick as thus high turnover rate
-Versatile in how you want to set up you grow op (i.e. vertical, buckets or just in Tupperware)
-Just one unit to clean instead of many heads like Aeroponics

Cons for Fogponics are:
-Foggers heats up which can destroy the nutrients and hurt the roots
-The frequency at which foggers currently vibrate create droplets 5-15 micron range which is great for seedlings as they only require water but as plants get older they require nutrients so the droplets need to be bigger (say 50 microns) to carry the nutrients.
-Ultrasonic foggers can't handle anything lager then 500 ppm because it will clog them and kills them

I have a few ideas how to fix the cons but I need to talk with someone who has working knowledge of how to design a piezoelectric transducer so see if my idea have any weight (such as being able to switch frequencies so it can switch from producing 5-15 microns to 50 microns).

Sorry for the wall of text, you made to the end without passing out from boredom thanks for reading.

tl/dr Don’t know what kind of engineer to talk to but need help on how to design an piezoelectric transducers (ultrasonic fogger) to use specifically for fogponics; such as changing the frequency so droplet sizes are bigger (50 microns instead of 5-15 microns) and thus can carry larger/heavier nutrients to the roots, avoid overheating water and be able to handle more than 500 ppm solution without clogging.

(p.s I see people talking about Ultrasonic Nebulizers, I am assuming they are the same thing as piezoelectric transducer (ultrasonic foggers)? )

 

[alec_t]

Can't help you on the piezo transducer, but something you might like to experiment with is a spinning disc atomiser, where drops flung off from the disc edge have sizes dependent on rotation speed.

 

[cowboybob]

Welcome to ETO, fogponicsguy.

(p.s I see people talking about Ultrasonic Nebulizers, I am assuming they are the same thing as piezoelectric transducer (ultrasonic foggers)? )

Yes, nebulizer its just a generic medical term for "fogger".

These guys (a site you may be familiar with):

https://www.rollitup.org/hydroponics-aeroponics/411708-can-ultrasonic-fogger-set-lower.html

discuss this issue and seem to think a piezo based nebulizer simply can't be used to produce droplets of the size you envision (50μ). That does not necessarily mean it can't be done but I do know piezos under a mechanical load tend to heat up as frequencies are lowered. The mechanical stresses on the crystalline structure get further from the resonant frequency thereby increasing friction in that structure.

Course, they willingly refer to themselves as "stoners" (not being critical, only quit smoking the weed 4 years ago), so their data may be flawed.

Anyway, this from Wikipedia (although the concept seems very likely to clog in your application):

"...Vibrating Mesh Technology (VMT)A new significant innovation was made in the nebulizer market around 2005, with creation of the ultrasonic Vibrating Mesh Technology (VMT). With this technology a mesh/membrane with 1000-7000 laser drilled holes vibrates at the top of the liquid reservoir, and thereby pressures out a mist of very fine droplets through the holes. This technology is more efficient than having a vibrating piezoelectric element at the bottom of the liquid reservoir, and thereby shorter treatment times are also achieved. The old problems found with the ultrasonic wave nebulizer, having too much liquid waste and undesired heating of the medical liquid, have also been solved by the new Vibrating Mesh nebulizers. A partial list of available VMT nebulizers includes: Pari eFlow,[8] Respironics i-Neb,[9] Omron MicroAir,[10] Beurer Nebulizer IH50,[11] and Aerogen Aeroneb.[12] As the price of the ultrasonic VMT nebulizers carry a higher price compared to the previous models, most of the manufacturers continue also to sell the more "old fashioned" Jet nebulizer."

 

[wizard]

Hello all never really done this before but here goes nothing, I am looking talk to an engineer (I have no idea what kind of engineer I am looking for) to help design piezoelectric transducer (ultrasonic fogger) for Fogponics. Fogponics is used to grow herbs/vegetables/fruits and is a form of Aeroponics that uses a piezoelectric transducer (ultrasonic foggers) to atomize the water into particles that are micrometres in size which is the size roots absorb water at.

Water droplet size is crucial, too large a water droplet means less oxygen is available to the root system too fine a water droplet such as those generated by the ultrasonic foggers (5-15 micrometres) produce excessive root hair without developing a lateral root system for sustained growth. High Pressure Areoponics makes mist of 5-50 micrometres micro-droplets which are necessary for long-term growing.

I have done extensive research on the pros and cons of fogponics mostly using http://ganjadigger.com which searches ICmag, Roll It Up, Grass City, THC Farmer, Cannabis, Cannabis Culture, Open Grow, Gardens Cure, 420 Magazine. Why these sites you might ask because they are really the only ones with people trying out this type of system and pushing it forward. At best the information on the site is fragmented with arguments for and against fogponics, I want to compile all the data I can mine from them and put it into a clear and concise all-encompassing manual for growing using fogponics and give it back to the communities because I believe sharing/open sourcing is the best way to innovation. These are my findings so far for Fogponics

Pros for Fogponics:
-Uses less water and nutrients, 70% less then hydroponics which already uses 70% less then traditional farming
-High Yield
-Growth speed on roots is amazing, large mass and very fuzzy; growth of stems is very quick as thus high turnover rate
-Versatile in how you want to set up you grow op (i.e. vertical, buckets or just in Tupperware)
-Just one unit to clean instead of many heads like Aeroponics

Cons for Fogponics are:
-Foggers heats up which can destroy the nutrients and hurt the roots
-The frequency at which foggers currently vibrate create droplets 5-15 micron range which is great for seedlings as they only require water but as plants get older they require nutrients so the droplets need to be bigger (say 50 microns) to carry the nutrients.
-Ultrasonic foggers can't handle anything lager then 500 ppm because it will clog them and kills them

I have a few ideas how to fix the cons but I need to talk with someone who has working knowledge of how to design a piezoelectric transducer so see if my idea have any weight (such as being able to switch frequencies so it can switch from producing 5-15 microns to 50 microns).

Sorry for the wall of text, you made to the end without passing out from boredom thanks for reading.

tl/dr Don’t know what kind of engineer to talk to but need help on how to design an piezoelectric transducers (ultrasonic fogger) to use specifically for fogponics; such as changing the frequency so droplet sizes are bigger (50 microns instead of 5-15 microns) and thus can carry larger/heavier nutrients to the roots, avoid overheating water and be able to handle more than 500 ppm solution without clogging.

(p.s I see people talking about Ultrasonic Nebulizers, I am assuming they are the same thing as piezoelectric transducer (ultrasonic foggers)? )

Hi fogponicsguy,

Actually the resonance frequency of an Ultrasonic piezo is narrow (this maximizes the mechanical vibration of a piezo). So to change the droplet size of the water you need several piezos with different resonance frequence, and of course drive each by a separated resonator circuit.
In an ultasonic fogger (or at least in those that I have used till now) the atomized water does not happen to get so warm. The piezo itself can be hot and even burnt if it happens to work without any water inside, but the atomized water is almost coo, but a chiller can be used if you'd like as well!
And finally as a guy who has worked on Fog Screens please take a look at th below link (I hope looking at this web site could give you some insight for your task):
http://www.finkbuilt.com/blog/diy-fog-screen/

Cheers

P.S: Not sure but maybe you could modify a "fog machine" and then use a chiller to cool the output and see what it brings as well (just a stupid idea)!!

 

[Externet]

Hi.

Am currently using this season, my Aerogarden 7 to germinate :

----> http://www.compostguy.com/images/aerogarden1.jpg

Modified with the fogger 'model M001' inside, instead of the now removed stock 'normal' hydroponics pump :

----> http://www.mainlandmart.com/foggers.html

And it does its thing well.

 

[KeepItSimpleStupid]

Why not use a nebulizer head and just create a auto-fill mechanism? See: https://justnebulizers.com/nebulizer-accessories/nebulizer-sets.html So a compressor, a nebulizer head and some mechanism to auto-fill the easy one. Not sure how to detect clogging. Pressure?

The heads are fairly simple since a member of my household uses one. Nutrients MIGHT cause clogging unless filtered.

 

[fogponicsguy]

Whoa this thread kinda blew up, not going to lie thought it was going to get buried with not replies lol but it didn't so thanks for replying everyone

@alec_t Thanks for the suggestion I had never heard of spinning disc atomiser when i googled it i didn't really find too much information, what i did find is that it seems to be used for applying paint to vehicles and the actual spinning disc atomiser is the size of a dump truck do you have anymore info on it, like could it just be a metal disk attached to DC motor using a some kind of regulator?

@cowboybob Thanks for the clarification on the Nebulizers helps a lot.

I have seen that thread before on rollitup the question never really gets answer kinda just turns into fighting when it finally does get sort of answered, the answer is along the lines of "No it won't work cause i have done lots of research *no proof to back it up" it's funny for stoners they usually aren't too relaxed when discussing fogponics.

Thanks for info on the the fact 'piezos under a mechanical load tend to heat up as frequencies are lowered'. I have actually checked the Vibrating Mesh Technology (VMT) and i pretty much came to the same conclusion that it would clog because the nutrients would be in the 500 ppm range. Although i would love to test it i don't think the company would send me a unit because i am not a medical company or a doctor (plus i think it probably would cost a lot and i am a poor poor student)

@wizard So instead of having one head that switched frequencies, i would require a unit with several head set to their own frequency with their own separated resonator circuit with a switch that would turn one head on and then the other off?

For the heat I have just seen several different people on the forums comments one way or the other with fogponics either the ultrasonic fogger is getting too hot thus the water is getting too hot or it's just fine, this is probably something i should test out myself not saying i don't believe you but seeing (or feeling in this case) is believing. As for the chiller i have actually seed a few people use them in their setup, i was hoping to avoid these for a few reasons one avoiding the extra cost as they can get very expensive, two avoiding an extra bulk on the system and three hoping to avoid another step thing that can break on the system.

@Externet Hey, I actually have the smaller system of that it was awesome while it lasted (i.e. i tore it apart lol) but a few questions are you able to grow anything like say cherry tomatoes or beans to cultivation and are you using your own fertilizer or still using the capsules from areogardens?

@ KeepItSimpleStupid How do this ones work? Sorry if it is a stupid question i just don't where the piezoelectric transducer are. Also do you know what size nebulizer head turns water into, say 5- 10 microns? and what size of ppm it can handle?


While searching this site for threads about ultrasonic foggers I found this thread https://www.electro-tech-online.com...er-design-with-piezocrystal-need-help.125195/ where user Sceadwian suggested this website **broken link removed** and they have a youtube https://www.youtube.com/watch?v=h7R0LzB98K4&list=ULGVSFG5MFjOI that shows a piezoelectric transducer slowed down to 60 Khz and it actually looks like the water is still atomized at 60 Khz and if at 1.6 Mhz water is 1-25 microns in size i can only imagen how big the water particles would be at that size

 

[alec_t]

could it just be a metal disk attached to DC motor using a some kind of regulator?

Yes it could. Recollections are hazy (it was 50 yrs ago!). I used a disc with a sharpened edge, about the size of a CD, spun at I think ~ 5k rpm and got water drops < 100 micron diam. For any one speed there was a range of drop sizes. Mean diam reduced as speed increased. I only ever used one disc size, but I assume the lower the rpm the greater the disc diam needed for a given drop size (hence the big industrial units you found).

 

[Externet]

...@Externet Hey, I actually have the smaller system of that it was awesome while it lasted (i.e. i tore it apart lol) but a few questions are you able to grow anything like say cherry tomatoes or beans to cultivation and are you using your own fertilizer or still using the capsules from areogardens? ...

Hi.
I do not grow in the modified 'aeroponics mode' on the AeroGarden7. Just use it for culinary herbs early germination in March and transplant outside (1 acre yard). When am done goes back to sleep in the attic until next year.

In hydroponics stock mode, the manufacturer claims it can grow cherry tomatoes, but the energetic cost of the unit on 24/7 is absurd. Better buy the handful of tomatoes at the market; or grow on a flower pot outdoors. Beans are way too cheap to bother, grow something worth it. I have been trying to find capers seeds, mission impossible so far.

I use a pinch of MiracleGrow fertilizer dissolved in tap water. There is nothing to clog with the submerged "ultrasonic" fogger piezoelectric disc (which is NOT ultrasonic; it is radiofrequency at ~ 2 MHz).
I do not use the stock AeroGarden baskets. I put the seeds inside split cotton balls wrapped in sponge to fit the holes, fog does not leak out that way. Water does not get warm to notice.
If you want my system, I will be done with it in a week to build a piezoelectric huge system.

 

[fogponicsguy]

@alec_t Well if it is something I can easily make myself say with a decent size eletcric motor and metal disk i will defiantly have to look into it, especially if allows easy control of the water droplet sizes. The only downside i could see with it is unlike iezoelectric transducer (fogger) which makes the water droplets that just float above the water which i then plan to move up a vertical pipe to feed the plants using pull from a small fan since they are so small. Using Rotary Atomization i imagen that the droplets would get splattered against the wall since they are being spun off a disk at high speed.

@Externet ah okay that is good, from what i have found from researching fogponics is that it is really good for germination but i am hoping to use it beyond that from seedling to cultivation so it might one day be used in vertical farming for growing. I have though of cutting the fertilizer i use in half as to help avoiding the clogging of the fogger since using it fogponics the plants absorb water faster because of the droplet size so i can refill the system more often. Sorry but i may have misunderstood the last part of your post but do you mean your building a fogponics unit when you say 'I will be done with it in a week to build a piezoelectric huge system.' if so i am very interested in following your build

 

[alec_t]

the droplets would get splattered against the wall since they are being spun off a disk at high speed.

Yup....unless you found a way of collecting them without them coalescing. Their radial velocity is impressive .

 

[Externet]

...@Externet ... Sorry but i may have misunderstood the last part of your post but do you mean your building a fogponics unit when you say 'I will be done with it in a week to build a piezoelectric huge system.' if so i am very interested in following your build

Yes, I mean will put the modified AeroGarden7 away and build a large aeroponics contraption for germination+growth using 'ultrasonic' fogger and fan recirculation.

 

[wizard]

@wizard So instead of having one head that switched frequencies, i would require a unit with several head set to their own frequency with their own separated resonator circuit with a switch that would turn one head on and then the other off?

Depending on your circuit design you could have One circuit capable of changing its swing frequency proportional to the resonance frequency of the piezos (something almost like a signal generator that gets a pot (you can use several buttons instead because your finall frequencies are known) to change the swing freq) or you can consider just separated circuits for each piezo.

Please notice that the swing frequency of each designed circuit must be accurately equal to the resonance frequency of each piezo, otherwise you would lose part of the energy\ power generated by each sensor (and hence no or a small amount of the fog would be created by your setup).