What will trigger a capacitance touch sensor?

[PVNRT4ME]

I've got an iPod Touch and am trying to create an electrical circuit that, when turned on, will trigger the touch sensor in a specific spot (the spot that whatever component of the circuit provides capacitance is resting on, I guess).

For the life of me, I cannot figure out how to trigger a capacitance sensor. I know what it needs; capacitance. Human fingers provide that. I've discovered that the negative side of a battery also works; but how can I control it?

 

[berkeman]

You can put an array of small metal squares over the spots, and use transistors to connect one square at a time to ground. The others will have some capacitance to ground, but much less than when the transistor is turned on.

 

[oswaler]

A capacitance touch sensor is triggered by a change in capacitance in a specific spot on its surface. This change can be caused by a variety of factors, including the presence of a human finger or a conductive material, such as the negative side of a battery, in close proximity to the sensor. To control the triggering of the sensor, you can manipulate the amount of capacitance in the specific spot where the sensor is located. This can be done by adjusting the distance between the sensor and the conductive material, or by using a material with a different level of conductivity. Additionally, some capacitance touch sensors have adjustable sensitivity settings that can be used to control the trigger threshold. It is important to carefully design and test your circuit to ensure that it reliably triggers the sensor in the desired spot.