A keyboard apparatus includes a fabric and switch units coupled to the fabric. Each switch unit includes a capsule containing an electrically responsive liquid, wherein the electrically responsive liquid causes the capsule to increase in rigidity in response to application of an electric field to the electrically responsive liquid. Each switch unit also includes one or more switches coupled to the capsule, wherein a selected pressure applied to the capsule activates or more of the switches underneath the capsule. The keyboard apparatus also contains electrical conducting lines connected to the switch units.