Using Javascript you would do something like this:

function OnTriggerEnter(otherObject: Collider){

if(otherObject.gameObject.tag == "Robot"){

blabla();

}

You would also have to create a tag and name it Robot, then select that tag on the object you want to collide. Also you might have to set one of the 2 objects that are colliding to be the trigger.

This is easy, for more information visit this link: http://unity3d.com/support/documentation/ScriptReference/Collider.OnCollisionEnter.html

Any questions, ask ;D Hope this help

Collider enter:

function OnColliderEnter (hit : Collision) { Destroy(hit.gameObject); }

Trigger enter:

function OnTriggerEnter (hit : Collider) { Destroy(hit.gameObject); }