Week 5 Researching technology

Milestone:
To assess the viability of my scent based design with regards to functionality and technology I had to do a lot of background research. I found several options that might work with the design, still allowing the dimensioning to remain as I intended it to be. By using a heating element similar to the ones used in electric cigarette's, the scent can be based on heating up oils or gels. As an alternative I could use heating coils, but this has to be tested and investigated further as the product will be placed on the users skin. Bluetooth is the best alternative for the wireless transmission as it is inexpensive, can be packaged in a compact manner and is automatic. The wireless range is about 10 meters, which should be sufficient for reaching sensors that are in the same room. 



The 'Sixth Scent' bracelet will have heating elements in the core, aiding the release of the scented oil. Electric cigarettes sometimes use ultrasonics to produce an inhaling mist through vaporizing a glycerine liquid into an aerosol mist. This is done in a similar way to a nebulizer or humidifier. Ultrasonics is also a trade term coined by the Ultrasonic Manufacturers Association and used by its successor, the Ultrasonic Industry Association, to refer to the use of high-intensity acoustic energy to change materials. This mechanism would need to be tested as there is no available research relevant to my project indicating whether this will work well with the scented gels. I would also like the heat-function to be strong enough to be noticeable on the skin of the user. If this technology is not feasible, the use of micro coil heating elements might be an option, but as I am finding it hard to find information about specific power-requirements this needs to be investigated further. The bracelet will operate through batteries, and whether these will be sufficient needs to be calculated. Here is a link to a website with information regarding micro heating coils (image underneath). http://www.rotfil.com/en/product.asp?idprod=37. This page has information regarding electric cigarettes.

One of the sensors can be used to detect differences in temperature. This sensor can be used on the outside of a water boiler for example. When the water has reached boiling temperature the sensor will communicate with the 'Sixth Scent' bracelet through bluetooth and let theuser know the water is done. This is a useful application for consumers that might be blind/def or both.  Here is a link to a site about heat-detecting components: http://www.atmel.com/dyn/products/devices.asp?category_id=172&family_id=705&subfamily_id=2267

 http://www.analog.com/en/index.html

The second sensor will have a built in microphone, to detect changes in the environment, e.g. when a dishwasher is finished. The sensor will communicate with the bracelet in the same way as the other sensors. A wireless microphone, as the name implies, is a microphone without a physical cable connecting it directly to the sound recording or amplifying equipment with which it is associated. Also known as a radio microphone, it has a small, battery-powered radio transmitter in the microphone body, which transmits the audio signal from the microphone by radio waves to a nearby receiver unit, which recovers the audio. Wireless microphones are widely used in the entertainment industry, television broadcasting, and public speaking to allow public speakers, interviewers, performers, and entertainers to move about freely while using a microphone to amplify their voices.

http://electronics.howstuffworks.com/search.php?terms=microphone

Bluetooth is essentially a networking standard that works at two levels:

• It provides agreement at the physical level -- Bluetooth is a radio-frequency standard.
• It provides agreement at the protocol level, where products have to agree on when bits are sent, how many will be sent at a time, and how the parties in a conversation can be sure that the message received is the same as the message sent. 
• The big draws of Bluetooth are that it is wireless, inexpensive and automatic. There are other ways to get around using wires, including infrared communication. Infrared (IR) refers to light waves of a lower frequency than human eyes can receive and interpret. Infrared is used in most television remote control systems. Infrared communications are fairly reliable and don't cost very much to build into a device, but there are a couple of drawbacks. First, infrared is a "line of sight" technology. For example, you have to point the remote control at the television or DVD player to make things happen. The second drawback is that infrared is almost always a "one to one" technology. You can send data between your desktop computer and your laptop computer, but not your laptop computer and your PDA at the same time.
•  One of the ways Bluetooth devices avoid interfering with other systems is by sending out very weak signals of about 1 milliwatt. By comparison, the most powerful cell phones can transmit a signal of 3 watts. The low power limits the range of a Bluetooth device to about 10 meters (32 feet), cutting the chances of interference between your computer system and your portable telephone or television. Even with the low power, Bluetooth doesn't require line of sight between communicating devices. The walls in your house won't stop a Bluetooth signal, making the standard useful for controlling several devices in different rooms. 
• Bluetooth can connect up to eight devices simultaneously. With all of those devices in the same 10-meter (32-foot) radius, you might think they'd interfere with one another, but it's unlikely. Bluetooth uses a technique called spread-spectrum frequency hopping that makes it rare for more than one device to be transmitting on the same frequency at the same time. In this technique, a device will use 79 individual, randomly chosen frequencies within a designated range, changing from one to another on a regular basis. In the case of Bluetooth, the transmitters change frequencies 1,600 times every second, meaning that more devices can make full use of a limited slice of the radio spectrum.
• When Bluetooth-capable devices come within range of one another, an electronic conversation takes place to determine whether they have data to share or whether one needs to control the other. The user doesn't have to press a button or give a command -- the electronic conversation happens automatically. Once the conversation has occurred, the devices -- whether they're part of a computer system or a stereo -- form a network. Bluetooth systems create a personal-area network (PAN), or piconet, that may fill a room or may encompass no more distance than that between the cell phone on a belt-clip and the headset on your head. Once a piconet is established, the members randomly hop frequencies in unison so they stay in touch with one another and avoid other piconets that may be operating in the same room. Let's check out an example of a Bluetooth-connected system.

http://electronics.howstuffworks.com/bluetooth2.htm