Imagination and creativity have always marked the path in the world of aesthetics; artists, designers and other creative individuals have found in the realm of computers a new canvas where illusions can come true, where new worlds can be designed and explored and where imagination can supersede or control the rules of physics. In this regard, one can speak of cyberart: it is a very expansive concept that includes the creation of interactive worlds. These worlds, by definition, need a way for users to become part of the art piece by modifying it trough time. Interactive techniques commonly used when developing human computer interfaces (HCI) for traditional virtual reality applications are not always suited for art applications. This is so because each art installation is unique and reflects the artist's point of view. This paper describes a particular interactive art piece, "Fluids" and how we solved the particular interface issues involved. We also discuss the process we followed for developing interaction hardware that must meet the requirements of this medium