Taste Sensor for the Propeller Chip
Humanoido
Posts: 5,770
I'm looking for a hobby taste sensor for the Propeller chip. Detected tastes can include sour, bitter, sweet and salt.
Comments
A small amount at a time could be dispensed on an artificial tongue and then auto-washed after the detection cycle in completed. The solution could have some viscosity so it would not drool.
The major taste groups are sour, sweet, salty, and bitter. It would detect salty substances (chips, ham, bacon, salty fish, Soya sauce, salad dressing), things like pieces of fruit that are either tangy/tart/sour like citrus (Rhubarb, lemon, lime, orange, grapefruit) or bitter (Brazil nuts or Filberts, vinegar, beer, bitter melon and bitter gourd (Asian)).
Sweet could include sugar, candy, honey, syrup, banana, ripe strawberry, chocolate frosting on cake, apple or cherry pie, soda pop). For now, it could stick to sampling liquids or food surfaces that are wet.
http://www.physorg.com/news203771636.html
The scientists built their sensor using the principle of a nanoscale field-effect transistor. In contrast to a current-controlled classical transistor, a field-effect transistor is switched by means of an electric field. At the core of the device are nanowires made of the semiconductor silicon. These were coated with a molecular layer made from special silicon compounds that contains amino groups (NH2). TNT molecules bind to these amino groups in the form of charge-transfer complexes. The binding process involves the transfer of electrons from the electron-rich amino groups to the electron-poor TNT. This change in the charge distribution on the surface of the nanowires modulates the electric field and leads to an abrupt change in the conductivity of the nanowires, which is easily measured. To improve the signal-to-noise ratio and thus increase the sensitivity, the scientists equipped their chip with an array of about 200 individual sensors. “We are thus able to analyze liquid and gaseous samples without prior concentration or other sample preparation at previously unattainable sensitivities,” says Patolsky. “We were able to analyze concentrations down to 0.1 ppt (parts per trillion); that is, one molecule of TNT in 10 quadrillion other molecules.” The sensor can be quickly regenerated by washing and is selective for TNT; other related molecules do not react the same way.
http://www.thefreelibrary.com/Electronic+noses+indicate+when+a+fruit+is+ripe.-a059174441
Researchers also are conducting experiments using a prototype hand-held nose developed by Cyrano Sciences Inc. (73 N Vinedo Ave., Pasadena, CA 91107), the production version of which may be available later this year, we're told. At Warwick, research has been carried out on the use of thin- and thick-film semiconducting materials for odor odor (o´der) a volatile emanation perceived by the sense of smell. Research is centered upon the use of arrays of metal oxide and conducting polymer odor sensors. The latter are of interest because their molecular structure can be engineered for a specific odor-sensing application. A number of electronic noses have been developed by the group. There are several laboratory-based instruments, one employing an array of 12 metal oxide sensors, and another employing an array of 24 conducting polymer sensors. The conducting polymer instrument is fully automated with three separate flow-injection lines and three vessels for odor samples. Several portable instruments also have been built, including a four-element tin oxide tin oxide (SnO), a polishing agent in the form of a purified white powder, prepared as a paste with glycerine or water. device, a six-element tin oxide electronic nose and four 12-element polymer electronic noses. Warwick scientists are open to collaborating with industry on the development of new odor sensors, materials and algorithms. The University of Warwick also will license some of the technology.
They have also developed Electronic Snot
http://thefutureofthings.com/pod/224/new-electronic-snot-developed.html
Researchers at The Universities of Warwick and Leicester developed an improved artificial nose using a mix of polymers that mimics the action of the mucus in the natural nose allowing them to pick out a more diverse range of smells.
Electronic snot. Whatever next!.
One problem with this is the tongue is a disposable one use only thing, unless the litmus comes in a large spool that can be dispensed in a small piece at a time for each taste, and then discarded.
One possible DIY approach might be to modify a microbe that will light up when it encounters your specific conditions, so your machine saliva could contain this sort of microbe. For example, people have made very sensitive sensors using Vibrio fischeri, which is bioluminescent. Genes from V. fischeri have been removed and are insertable into E. coli.
http://www.carolina.com/product/glow+in+the+dark+transformation+kit.do?keyword=glow+in+dark&sortby=bestMatches
Another approach might be to use GFP, green fluorescent protein, which is also a possible DIY project.
http://www.carolina.com/product/green+gene+colony+transformation+kit+student+teach.do?keyword=gfp&sortby=bestMatches
With GFP inside a microbe you can set things up to sense a specific chemical, and when you flash it with blue light, it emits a specific wavelength that gives you your indication.
While smelling/tasting to us animals is a no-brainer, it's really a very complicated sensory system that uses a myriad of molecular receptors. Trying to build such a thing from scratch would be a daunting task, but hijacking a preexisting biological system might be somewhat doable if you take the time to learn.
prove informative --
http://www.bbc.co.uk/news/science-environment-12827893
Okay, I just tasted it. The Propeller Chip tastes a little sour.
Either that, or I didn't get all the flux off of it.
Doesn't sound like a very fun hobby!
Edit, my bad, it was a scanning electron microscope - http://www.youtube.com/watch?v=sG7G3LN_SN8