Pressure sensor, touch substrate and touch display device

A pressure sensor, comprising:

• a substrate,
• an active layer, which is provided on the substrate;
• a gate electrode, which is stacked with the active layer and insulated from the active layer;
• an elastic layer, which is arranged between the active layer and the gate electrode in a direction perpendicular to the active layer so that the gate electrode is insulated from the active layer;
• and
• a source electrode and a drain electrode, which are spaced from each other and are both electrically connected with the active layer,
• wherein if a pressure is applied to the pressure sensor, a thickness of the elastic layer is decreased,
• an orthogonal projection of the active layer on the elastic layer is substantially located within the elastic layer,
• the active layer is provided on a side of the elastic layer facing the substrate, the gate electrode is provided on a side of the elastic layer facing away from the substrate, and
• the elastic layer covers and directly contacts a surface, parallel to the substrate, of the active layer but does not directly contact a side surface, perpendicular to the substrate, of the active layer,
• the elastic layer covers and directly contacts surfaces, parallel to the substrate, of the source electrode and the drain electrode and surfaces, perpendicular to the substrate, of the source electrode and the drain electrode, and
• the elastic layer further covers and directly contacts a portion of the substrate.