The opening and closing of doors have been around for thousands of years. People have learned to interpret the heaviness of doors and the strength that must be exerted to open them. Heavy doors are associated with value, demarcation and danger. Door! is a mechatronic enhanced door. To open it requires users to overcome an perceivable resistance. This way, simple information can be communicated to users, such as a danger in the next room.

The door handle is an essential interface for opening doors. Application of force to the handle leads to the door lock opening and thus of the door. Handle! enhances the classic door handle with the capability to adjust the resistance that must be overcome to push the door handle. Users perceive this resistance as a proprioceptive stimulus and learn to interpret it. Not perceptible by third parties, simple information such as warnings can be privately communicated to users.

Classic navigation systems determine the position of a user and guide them visually and acoustically to destinations. The audio-visual communication of these systems can bind the attention, and their use can lead to danger to users due to visual and cognitive distractions. Trolley! is a kinesthetic navigation system in the form of a trolley that guides users to a destination simply by introducing frictional resistance into the individual wheels of the trolley.

Knobs are everywhere! They allow us to adjust our environment to our needs. A bright light is dimmed, a heater and bass boxes are turned up – it's always us who are in charge! Knob! turns the game and slows us down, regulates us down and prevents us from energetic stupidities! The dimmer increases resistance when being turned into states that the system identifies as unecological, making it harder to turn things further up.

The ease with which drawers can be opened without strength is considered a requisite for a barrier-free and joyful drawer. Drawer! defies this paradigm and makes access to the contents of drawers perceptibly more difficult by introducing an adjustable resistance. Thus, in the process of opening a drawer, simple warnings can be communicated that should be heeded when handling the drawer's contents.