Power Fist (Soft Sensor Project)

Having recently read about the fabulous TEI Superhero Design Challenge
(http://www.tei-conf.org/11/participation_/design-challenge/), I’ve been
wanting to create 
my own piece of superhumanizing attire.

Enter PowerFist, a flashy glove that imbues its wearer with ridiculously
awesome strength! As the wearer closes their fingers into a fist, the glove
will ‘charge’, and the 
emblem (a ‘P’, of course) will glow ever brighter,
showing its current power level.

Materials:

Black knit glove
Velostat
Neoprene (two sheets)
Conductive Thread
Conductive Fabric (iron-on)
Unholstery Foam
Red fabric
 (for the ‘P’)

3-AAA Battery Pack
Insulated wire
Circular LED array (scavenged from a flashlight)

Iteration 1:

The main component of this project was an LED array that would
change its 
brightness depending on the pressure registered by a
custom-made soft 
sensor. I used the tutorial for a Neoprene
Pressure Sensor (from How To Get What You Want,
http://www.kobakant.at/DIY/?p=65) to create the first iteration
of this component.

Method:


Step 1:
Cut two rectangular pieces of neoprene, and cut a tab out on each piece.

Step 2:
Using an iron, a small square of conductive fabric was attached to each tab

Step 3:
For each neoprene piece, conductive thread was sown on, with 4 lengths
parallel to eachother (and angled diagonally), and then attached to the
conductive thread on the tab.  The thread pattern was identical for each piece,
so that, when the two pieces of neoprene were placed against eachother,
the threads would form a network of X’s (this was to ensure that a circuit
was formed

Step 4:
A piece of velostat was sown over the conductive thread on one of the
neoprene 
pieces

Step 

5.
The two neoprene pieces were sown together to form
the soft pressure sensor. The soft sensor was then attached in series to the
battery pack and the LED array. This iteration proved unsuccessful — the
LED array did not light up, and was most likely 
due to the fact that the
resistance of the conductive thread, together with the velostat, 
reduced
the current to an amount that wasn’t sufficient to drive all 15+ LED’s on
the array (even with maximal pressure applied).

Iteration 2:

For the second iteration of the soft sensor, I decided to forego conductive
thread 
in favor of conductive fabric, to reduce resistance. This new soft sensor
was structurally similar to the one from Iteration 1, except that a piece of
conductive fabric was used in place of the network of conductive thread.

This worked perfectly! The LED array now gradually glowed or dimmed in
response to applied pressure.

Placement of Components:

The soft sensor was attached to the palm of the glove, in the area directly
beneath the fingers. The LED array was fitted with a layer of upholstery foam
(used as a diffuser), and affixed to the dorsal side of the glove. The battery
pack was velcro’d onto 
the wrist section of the glove. All these components
were then connected together electrically with wire.

>>> See the video! <<<

Soft Sensor

Watch youtube video for details:

12 hour circuit

My intention for this project was to put my ‘ear sensor’ to work but unfortunately, it didn’t work. There wasn’t enough pressure inside the ear to keep the LED lit. I could have spent many hours trying alternate methods but given my time restraints, I decided to place the sensor inside the heal of my shoe. All went well.  Initially, I put the battery on the outside of the shoe but it didn’t look so great so I put in on the inside.  There is a slight discomfort that can be rectified if I rotate the battery holder.

conductive felt, je t’aime

I’m going to be making the majority of my soft cyborg’s nose out of conductive felt so that it’s one big force sensor. I started to play around with making conductive felt using bronze wool and merino wool. I found a Canadian supplier to order bronze wool from; it’s pricey ($9/3 pads) but it cards way better than steel wool and is much easier on the hands.

Initially I just played around with carding and felting the bronze and merino wools together. I used too much bronze wool and there was no resistance. I was much more meticulous the second time around. An Instructables tutorial on making conductive felt suggested using a 2:5 ratio, bronze wool to fleece. I went with 8g of bronze wool and 20g of merino wool. (The tutorial also said that this conductive fleece could be spun—something I will have to explore further at a later date.)

Materials & Equipment

  1. merino wool
  2. fine bronze wool
  3. scale (I used a digital scale the second time around)
  4. hand carders (i.e. cat brushes–the bronze wool will wreck real carders)
  5. felting needles and tools (optional but they make felting much faster)
  6. a piece of foam (for felting on)

materials & equipment

Conductive Fleece

The bronze wool needed to be teased apart a bit but aside from that, it blended easily with the wool fibres.

Bad Conductive Felt

While my first attempt at making conductive felt was a flop, I did figure out that the felt works better when it is loosely felted. I got a bit of variation in my reading with the thicker section of the felt rectangle. The ball’s reading did not change at all.

electric scale

Good Conductive Felt

Less bronze wool in this batch. I might even try a little less. The flat circle provided consistent variation in its resistance level when touched. The ball was a bit trickier, sometimes there was resistance, sometimes there wasn’t. Also, the ball’s resistance reading changed depending on how densely the fleece was felted. Structurally I need my soft cyborg’s nose to be able to be squeezed repetitively, however if it is too dense I won’t get a resistance reading. So I’ll try less bronze wool next.

Circuit

I used a simple force sensor circuit to test the resistance of the conductive felt. Here’s the code:

/*
AnalogReadSerial
Reads an analog input on pin 0, prints the result to the serial monitor

This example code is in the public domain.
*/

void setup() {
Serial.begin(9600);
}

void loop() {
int sensorValue = analogRead(A0);
Serial.println(sensorValue, DEC);
}

carded conductive fleece

carded conductive fleece (detail)

good conductive felt

soft circuit

Time for a little ACDC!

It’s never too late (or too early) to rock! This “headbanging” sensor provides heavy guitar riffs whenever you feel so inclined to rock out. Portable, wireless, lightweight. Now you have no excuse.

Parts:

  • Lilypad Arduino
  • Lilypad Xbee
  • 2 Xbee Radios
  • Xbee Explorer Breakout Board
  • FTDI Breakout Board
  • 9V battery + holder
  • Flex Sensor
  • 100k pulldown resistor
  • Wires

Heavy Metal Circuit

The flex sensor is a small conductive film strip applied length-wise at the base of the neck.  Each time the head is thrust forward (chin moving downward), the flex sensor changes in resistance.  Once it reaches a certain value, Processing triggers a guitar sample for you to rock out to.

Continue reading Time for a little ACDC!

Blush – Soft Sensor

For my soft sensor project, I constructed a mask which has a soft sensor embedded in the lips.  When the lips are touched or kissed, the cheeks of the mask will blush via red LEDs on the inside of the mask.

Blush works best in lower lighting conditions and is, arguably, the creepiest thing that I have yet made.

Watch the youtube video here!

Soft Sensor – HEAD

The part of the body I chose to do a pressure sensor for is the head. The concept that I came up with was an anti-napping sensor that, when attached to a buzzer, would help to prevent in-class/at-work napping. The sensor is a “Z” shape (Zzzzz….of course!) that can be attached to a headband, bobby pin, or secured to the inside of a hat.

Zzzzzz....

The user places the sensor on the part of their head they are most prone to falling asleep on, such as the side, back, or forehead. When the user drifts off and leans their head against something, the sensor is activated and the user is buzzed awake.

Soft Switches

Here are some of my soft switches! Still making interesting wearables, but I wanted to post my progress.

Sensor 1. This sensor works but i sewed the pieces too tightly and used too much conductive fabric. Practice round 1.

This is the second sensor. Its cool cause its round. Its for my kegal sensor so it works in the 360 degrees.

Sensor 3: THis time I sewed the piece more loosely and used less conductive material. I attached a coin cell battery and a speaker to play sound, however with the velostat there was too much resistance to power. damn.

Final Version= awesomeness: I used 2 small strips of conductive fabric, and sewed the two pieces very loosely they work perfectly. The sensor spot was for the temples, so I'm going to cut it to size and shape to create a headpiece.

Ear Sensor

My husband snores and I’m often stuffing ear plugs in my ear to block the sound. I thought it might be fun to attach this sensor to the end an ear plug and an LED light to the other. When the sensor and ear plug are inserted in the inner cavity of my ear, the LED light would go on.

This special ear plug would function in two ways. Firstly, by looking in a mirror, I can tell if the ear plug has made a good seal inside my ear. A weak light means the seal is bad and and strong light means the seal is solid and a good night’s sleep is imminent. Secondly, the light will notify anyone entering the room (like my son) that I am in a deep slumber.

Materials: Velostat, hand-felted wool, thread, conductive fabric.

Another possibility for this sensor design would be to eliminate the commercial ear plug and make the sensor cylindrical like the commercial ear plug since felt is wonderful at muffling sound.

Ear Sensor

Ear Sensor with Ear Plug

Sensing your baby cows…

The Calf.

An unusual spot on the body to pay too much attention to, and that’s probably why it intrigues me.

Anyways, the first sensor I made was too large, and I cut it down before taking photos.

at rest (02.2)

simply pressing on the sensor (00.6)

where it's attached/located: back of the leg, below the knee, on the largest part of the calf muscle

view from the back

at rest (02.7)

knee bent & muscle flexed (00.7)

A sample text widget

Etiam pulvinar consectetur dolor sed malesuada. Ut convallis euismod dolor nec pretium. Nunc ut tristique massa.

Nam sodales mi vitae dolor ullamcorper et vulputate enim accumsan. Morbi orci magna, tincidunt vitae molestie nec, molestie at mi. Nulla nulla lorem, suscipit in posuere in, interdum non magna.