whether Muslims should pray using the prayer rug?

Muslim worshippers praying on the rubble, image source : aljazeeraenglish

Whether Muslims should pray using the prayer rug or Sajjadah ?
 
The answer is no.

1. When we prayers,  we are not required to use a mat or other base,
because it uses a mat or other mat prayer is not a requirement.
The Prophet said, "I was given five things which have never given to anyone ...", of which he says, "And God made ​​the earth as a place of prayer entirely, so if there is one of my people get prayer time then let him pray wherever he is. "(Narrated by Bukhari)

In this hadith, the Prophet does not require a person to use a prayer mat, if he gets time to pray then let him pray there (except of course forbidden places for pray there, such as lavatories, etc.).

The practice of the Prophet and his companions before, are also often prayed on the ground, even when land is muddy due to rain ...

2. use mats or terms now with sajjadah, prayer is not a legitimate requirement, nor mandatory cases are not even in the sunna of the prophet, even some of the scholars stated makruh, if the mat is to make us negligent and not khusu (focus) in the prayer, such as mat a pictorial or patterned with the colors, as in what happened to the Prophet as a gift of cloth striped from one of his companions, he ordered them to return it because it's dereliction of his prayer,.