He began with works half-way between art and design, exhibited at various events, including: the Venice Biennale, Documenta 8 Kassel, the Milan Triennale 82-84-86, and the Rome Quadriennale 1988.
His personal exhibitions include those at the Musée des Arts in Lyon and the Vitra Design Museum. In 1984 he conceived and designed the manifesto exhibition "Neo-Merchandise: Design of Invention and Artificial Ecstasy", presented at the Milan Triennale and the Centre Pompidou in Paris; it became an international landmark of “techno-poetical, ironic and inventive design". 
Santachiara has also been curator of numerous other exhibitions: in Tokyo, of  "Signs of the Habitat" at the Grand Palais in Paris (1987), at the Berlaghe Museum in Amsterdam (1988) and in Barcelona (1990);  “The New Persona” at the Leopolda Station in Florence (1997) and of “Rooms and Secrets” at the Rotonda della Besana in Milan (April 2000).
His objects have been exhibited or are exposed in the permanent collections of various museums, including: the MoMA in New York, the Musée des Arts Decoratifs of the Louvre in Paris, the National Museum of Modern Art in Tokyo, the Museum of Lyon, the Museum of Frankfurt, the Vitra Design Museum, the Philadelphia Museum and the Collection de Design du Centre Pompidou.
He has also designed interiors, including: the Chartreuse of Avignon, a museum of magic in Blois for the French Culture Ministry, L’Art Hotel in Dresden and street furniture for the square of Toyama in Japan.
He worked on the corporate concept of the Banca Generali and a chain of online banks.
He has collaborated, and still does, with Italian and foreign firms on design, research and the creation of new products, including: SniaViscosa, the Fiat Style Center, the Montedison Culture Project, the French Culture Ministry, Artemide, Swatch, Mandarina Duck, Rosenthal, Panasonic, Domodinamica, BPT, Vitra, Campeggi, Superga, Bang-Olufsen, Banca Generali, è De Padova, Chrysler/Benz, Foscarini, Marutomy, Baleri Italia, La Murrina, Serralunga, Bonaldo, Magis, Zerodisegno, Post Design, Polsit, Naos.