Are there any remote stand applied to any size of aircraft that uses the mechanical movement which allows the steps to transfer passengers safely down or up without any efforts? In other words, an escalator that allows the passengers to use it to get-off or inside the aircraft in the remote stand area.
Mobile escalators for passenger boarding exist. By the looks of the following image, they are not exactly a new invention:
It seems, today they are mostly used in Saudi Arabia. Thyssenkrupp is still producing these for the Boeing 747SP:
According to this article, the Saudi royal family is also using mobile escalators by TEC Hünert:
The greatest possible degree of convenience for passengers when entering or leaving a parked aeroplane is almost certainly that provided by the mobile escalator version of the TEC Hünert passenger stairs. It enables the passengers to reach the aeroplane door with a minimum effort. The passenger is raised from the ground to the lowest part of the escalator by a lift installed in the place of some of the lower fixed steps. Furthermore there are other variations that for every order can be adapted flexibly. In particular for mobile escalators high-value components and materials are used to guarantee the highest level of comfort and passenger safety, ensuring an exclusive prestige object for every airport.