The PICO project aims to detect dark matter particles using the bubble chamber technique. The experiments are installed at a depth of 2 km in the SNOLAB underground laboratory at Sudbury, Ontario, Canada. The PICO collaboration has successfully operated several bubble chamber searches. The most recent two dark matter search experiments are a bubble chamber filled with ~57 kg of C3F8, and a chamber loaded with 3 kg of CF3I. PICO provides the best sensitivity to spin-dependent nuclear couplings from Weakly Interacting Massive Particles, presently favored dark matter candidates.
Currently, PICO-40L, a new bubble chamber design is being commissioned in SNOLAB. A much larger version of the experiment with up to 500 kg of active mass has been recently funded, and is under design. Construction of PICO-500 at SNOLAB is to begin in the near future.