Encourage children to use their entire bodies to explore the sensation of touch. Have each child lie on a carpeted floor face down or face up and demonstrate the motions of breaststroke swimming. Their arms and legs will brush the carpet and allow them to feel the texture while in motion. Tell them to move slowly to get the full effect of the texture and also to prevent rug burn. Use different types of carpet to add variety, but be sure each one is clean and no one is allergic to it.
Squirt a generous amount of foam shaving cream onto a plastic tray or other flat surface. Encourage the kids to run their fingers through the foam, spread it around or trace patterns or words into it.
Give each child a plastic container large enough for their hands to move around in and deep enough to contain the sand without straining little wrists. Let the children grab handfuls of sand, let it slip through their fingers, trace designs into it or find buried items. You could substitute coffee grounds or seeds for the sand, although the types of activities depend on the fineness of the grains. You could also use a pre-made sand table to reduce the potential for messes.
Lay a baby pool on the ground outside and fill it halfway with water. The kids can then dip their hands in the water, scoop it into their palms or make light splashes. If the pool is large enough, the children can play inside it to further explore the sensation of water. Like the sand table, a pre-made water table can suffice if you can't work outdoors.
Make slime for children to scoop, squeeze and generally explore its goopy texture. For each child, mix one cup of cornstarch and 1/4 cup of water with a few drops of food coloring. Let the children sprinkle glitter into the slime to add some sparkle.
Let the kids play with clay or dough. You can incorporate this into making bread or pizza as a group. Making pizza provides an additional tactile experience when handling the toppings; just be sure everyone's hands are clean.
Have the kids sit in a circle and close their eyes. Pass around bowls containing different materials, such as pasta, flour, beans and rice. When a child receives the bowl, he has to guess what's inside based purely on touch.