Graphite Touch Button: High Conductivity & Faster Response

In summary, the graphite touch button has high conductivity and therefore can be used to create a touch button with a low resistance. However, the touch button becomes unreliable after becoming cheap.
  • #1
graphite has high conductivity , so i though of making a touch button out of a pencil drawn pattern on the wall.the pattern is shown below.
when not touched -resistance between ends of the pattern >200Mohm (exceeds dmm limit)
when fully pressed - resistance between ends of the pattern = 1.3 Mohm.
but Vout rises after delay or falls after delay of some 100 ms.due to high impedance
this pattern connects skin resistances in parallel
can someone suggest a better pattern ( of lower end to end resistance) ?
for faster response
Last edited:
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  • #2
Hi hackhard. You probably have the transistor drawn incorrectly on your schematic.

I like your experimental bent, but a problem with a graphite pattern is that it will sooner or later probably smudge and establish a bridge between the tracks.

In future please keep images to under about 1000 pixels across, otherwise the thread gets displayed in tiny sized print to accommodate the oversized image on our screen.
  • #3
Search : ' electroconductive ink pens '
  • #4
Nidum said:
Search : ' electroconductive ink pens '
its very costly
mine is a cheaper solution
  • #5
hackhard said:
its very costly
mine is a cheaper solution
but not reliable ... cheapness come with disadvantages as @NascentOxygen said
  • #6
Here is a very different approach to do what you are doing. Perhaps you could have fun with a project to do that.

Jonathan Coleman's research group at Trinity College Dublin discovered that Silly Putty "becomes an incredibly sensitive strain detector that can track blood pressure, heart rate, and even a spider's footsteps" when mixed with graphene.

Popular Science reports:That graduate student, Connor Boland -- who has since earned his doctorate -- made a batch of graphene in water and added the Silly Putty polymer. As he mixed them, the graphene sheets stuck to the polymer, creating a black goo the researchers dubbed "g-putty." When they ran an electrical current through the g-putty -- graphene-infused polymers can conduct electricity -- they discovered an extraordinary sensitivity. "If you touch it even with the slightest pressure or deformation, the electrical resistance will change significantly," Coleman says. "Even if you stretch or compress the Silly Putty by one percent of its normal size, the electrical resistance will change by a factor of five. And that's a huge change." That change makes g-putty about 500 times more sensitive than other deformation-detecting materials, which would respond to a similar compression with a mere one-percent change in electrical resistance. The results were published in the journal Science.

Graphene has been made with pencil lines and scotch tape.
  • #7
thanks for help. I've decided to use conductive ink
  • #8
conducting paint is too expensive.
are there any other alternatives to copper foil strips or Bare conducting paint
  • #10
If you want resolution try making a lense to spread out a cheap dollar store solid state laser onto a inner reflective box frame and lining the inside parameter with a grid of cut mirror reflector's each precisely cut at width and angle's prime to each other and spaced at exact intervals, with incident angles toward two or more LDR(light dependent resistors) and coordinates of blocked pulse's like finger tips can be extracted easily though any serial adc.
  • #11
Try increasing R2 to 220K and pulldown to 10 meg ?

Related to Graphite Touch Button: High Conductivity & Faster Response

1. What is graphite touch button and how does it work?

Graphite touch button is a type of touch-sensitive button that utilizes the conductive properties of graphite to detect touch. It works by having a layer of graphite sandwiched between two layers of insulating material. When pressure is applied to the button, the graphite particles come into contact, creating a conductive path and registering the touch.

2. What are the advantages of using graphite touch buttons?

Graphite touch buttons have several advantages over other types of touch buttons. They have high conductivity, which means they are very responsive and require less pressure to activate. They also have a longer lifespan compared to other types of touch buttons, making them more durable. Additionally, graphite touch buttons are resistant to moisture and temperature changes, making them suitable for various environments.

3. How does the high conductivity of graphite touch buttons benefit users?

The high conductivity of graphite touch buttons allows for faster response times, making them ideal for applications where quick and precise touch input is required. This can include touchscreens, gaming devices, and various industrial and medical equipment. The high conductivity also ensures that the button will continue to function reliably even with frequent use.

4. Are there any limitations to using graphite touch buttons?

One limitation of graphite touch buttons is that they may not be suitable for use in extreme temperatures. Graphite has a low melting point, so it may not function properly in very high temperatures. Additionally, graphite touch buttons may not be as sensitive to light touch compared to other touch button technologies. However, advancements in technology are continuously addressing these limitations.

5. Can graphite touch buttons be used in different shapes and sizes?

Yes, graphite touch buttons can be customized to fit different shapes and sizes, making them versatile for various applications. They can also be integrated with other technologies, such as LED lights, to create a more dynamic user experience. The flexibility of graphite touch buttons makes them a popular choice among designers and manufacturers.

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