Archive for the 5. Treasure Hunt Category

Treasure Hunt

Posted in 5. Treasure Hunt on October 19, 2009 by Rohit

I used Paul’s idea of a Google Spreadsheet. Here’s the link:

This was a great exercise to find out a couple things:

  1. it is very difficult to find the cheapest items. I absolutely did not succeed in finding the cheapest, and considering some of the search functions of these sites I would probably be spending $100’s more on some big projects if I were to actually buy all this stuff.
  2. Google is still awesome

My reviews of some of these sites:
Great site, very easy to use and find parts and especially to find some cool new parts. For our class purposes and really any beginner electrician/robot-maker this site would be recommended.
If this is the haven for hobby enthusiasts…I never want a hobby. Terrible cluttered site that has possibly the worst search function ever. I’m sure its useful for some but for someone quickly looking for some cheap gadgets I did not have the patience to sift through this stuff.


Treasure Hunt

Posted in 5. Treasure Hunt on October 17, 2009 by lukekambic

I compromised on some of the prices to get better values. 

Bend / flex sensor      The $4.00 out-of-spec sensor would often suffice.

Fabric/stretch sensor   

This was almost the only source of small quantities of conductive rubber I could find. Making a stretch sensor is as easy as attaching terminals to the ends of a strip of conductive elastomer, so that’s what I looked for. Apparently anti-esd rubber bands have resistance in the megohm range, which is not as useful. One $8.00 sheet could make dozens of sensors.

Electroluminescent “wire” (EL-wire)

Alcohol sensor


Linear actuator

This one allows precise position control:

This doesn’t:

Fiber optic cable

Tiny potentiometer

Bag of small potentiometers:

Single tiny potentiometer:    

Conductive fabric:     Cheap tacky metallized craft fabric would probably work for some applications.

Thermochromic paint/dye    Nice minimum quantity, and you can easily choose the intensity of the tone by adding the appropriate amount of medium.

Nitinol / shape memory alloy wire  

Conductive paint      Is the RF shielding stuff conductive enough to handle useful current? If so, it’s a better value if you need a lot.

Neodymium magnets      I ordered some from here and they’re the real deal.

Copper tape / copper foil

Conductive adhesive:

Minimum price for a roll:

Tilt sensor

$0.25 and detects on two axes. Probably not very reliable.

Peltier Junction

These are sweet.

Weird Applications:

What can’t you use with an Arduino? With a big enough semiconductor switch, you could control a Transcranial Magnetic Stimulation coil.

Psychedelic Bong Smoke Machine Thing + Treasure Hunt

Posted in 5. Treasure Hunt on October 17, 2009 by melloko

Bend / flex sensor 4.5″: ($9.95) As the sensor is flexed, the resistance across the sensor increases.

Fabric/stretch sensor 2″ ($.8.95): When relaxed the sensor material has a nominal resistance of 1000 ohms per linear inch. As the stretch sensor is stretched the resistance gradually increases.

Electroluminescent “wire” (EL-wire) 3.2mm ($1.50): A wire that gives off a bright neon light glow.

Alcohol sensor: Sensor provides an analog resistive output based on alcohol concentration.

24 VDC Type Solenoid ($1.50): a loop of wire, often wrapped around a metallic core, which produces a magnetic field when an electric current is passed through it.

Linear actuator ($4.99): A linear actuator is a device that applies force in a linear manner, as opposed to rotationally like an electric motor.

Fiber optic cable ($0.50): functions as a “light guide,” guiding the light introduced at one end of the cable through to the other end.

Tiny potentiometer ($.0.50): a three-terminal resistor with a sliding contact that forms an adjustable voltage divider.

Conductive fabric ($3.95): a device used to prevent electrostatic discharge (ESD) by safely grounding a person working on electronic equipment

Thermochromic paint/dye ($22.99):  change color due to a change in temperature

Nitinol / shape memory alloy wire ($1.80): an alloy that “remembers” its original, cold, forged shape, and which returns to that shape after being deformed by applying heat.

Conductive paint ($7.50):

Neodymium magnets ($.0.10): currently the strongest type of permanent magnet.

Copper foil ($1.09): 0.003″ Thick x 3″ wide

Tilt sensor ($5.23): can measure the tilting in often two axes of a reference plane in two axes. In contrast, a full motion would use at least three axes and often additional sensors.

Peltier Junction ($12.95): the direct conversion of temperature differences to electric voltage and vice versa. Can be used to generate electricity, to measure temperature, to cool objects, or to heat them or cook them.

Interesting Component: Sun Tracking Solar Panel w/ Arduino

Most Bizarre Component: Psychedelic Bong Smoke Machine Thing

Here’s a video that describes the components in it.

Treasure Hunt! (a bit late!)

Posted in 5. Treasure Hunt on October 10, 2009 by zingzhang

Bend / flex sensor – $4 for “out of spec”, $9.95 otherwise

Fabric/stretch sensor – $1.50 per inch or build your own!

Electroluminescent “wire” (EL-wire) – $1.05 / foot

Alcohol sensor – $4.50

Solenoid – $1.50

Linear actuator – $4.99 (10 available)

Fiber optic cable – $4.99

Tiny potentiometer – $0.50 (SALE)

Conductive fabric – $1.95 per linear foot

Thermochromic paint – $22.99

Nitinol – $1.22 per 3 feet

Conductive paint – $18

Neodymium magnets – $0.10

Copper tape – $1 per yard

Tilt sensor – $5.23

Peltier Junction – $8.95

Bizzare use of an arduino – to program electronic instruments such as this guitar or this drum

Treasure Hunt

Posted in 5. Treasure Hunt on October 8, 2009 by Andrew Ngan

Flex sensor – $12.30

4″ Flexible stretch sensor – $10.95

Electroluminescent “wire” (EL-wire) – $0.88 per ft (100ft min)EL-wire – $0.99 per ft

Alcohol sensor – $4.95

Solenoid – $1.20

Linear actuator – $39.95

Fiber optic cable – $0.50

Tiny potentiometer – $0.99


Thermochromic paint/dye – $22.99

Nitinol / shape memory alloy wire (50 ft) – $24.99 / Nitinol wire – $17.62

Conductive paint – $12/30g

Neodymium magnets – $1.50

Copper tape / copper foil – $7.49 (15ft)

Tilt sensor – $1.90

Peltier Junction – $39.99 for 4


Arcade Joystick

Assignment 5: Treasure Hunt

Posted in 5. Treasure Hunt on October 6, 2009 by zhixunhe

1) Flex Sensor 4.5’’ $12.95

2) Flexible Stretch Sensors $8.95

3) Electroluminescent Wire $11.99
CrazyPC Blue EL Neon Wire Kit

4) Alcohol Gas Sensor MQ-3 $4.50

5) Solenoid  $1.5


6)  Linear actuator $9.95

Miga NanoMuscle

7) Fiber optic cable        $0.68

Single Mode Simplex Cable

8) Tiny Potentiometer    $0.98

1K Ohm Mini Trim Potentiometer

9) Conductive fabric      $17.06
3M 9712 XYZ-Axis Electrically Conductive Tape

10) Thermochromic Paint      $22.99

Thermochromic Temperature Color changing paint

11) Nitinol Actuator Wire $10.35

12)Conductive Paint $7.50

13) Neodymium Magnet $8.72

14) Cooper Foil $1.09

15) Tilt Sensor $14.95

16) Peltier Junction $15.95

The most interesting device I found is the sensitive fingertips. It can be used by children and their piano teachers to visualize the difference between “p” piano(soft) and “f” forte(hard). People can see the strength of their fingertips on the screen when playing piano with the gloves.

Treasure Hunt

Posted in 5. Treasure Hunt on October 5, 2009 by Paul Shen

My Google spreadsheet with links and prices