The $100 million Breakthrough Starshot program has issued a request for proposals.

Timeline

The next 5 years to determine the feasibility of both laser and sail. (Starshot's sail committee, a photon engine committee and a systems engineering committee.)
Tthe goal from years 6 to 11 is to build a low-power prototype for space testing.
A full scale laser system is to be built over the next 20 years
Launch of a starchip interstellar mission in about 30 years.

The RFP statement of key issues involved in identifying candidate materials and designs:

Design of a reflector consistent with the mission requirement of achieving 0.2c for ~1g payload and LightSail area of over 1 m2
Design of passive, adaptive or active features that enable or enhance stability, damage resistance, thermal robustness, and durability under deformation
Assessment of candidate materials (including thin-films, micro/nanopatterned structures, 2D materials) for thermal/mechanical stability
Development of measurement techniques and protocols for LightSail material properties (absorption, reflectivity, temperature, stress state, etc.)
Identification of materials for which scale-up and manufacture at the over 1 m2 scale is feasible
Materials that facilitate the integration of the LightSail with the Starchip
Development of the next generation Starchip scale spacecraft with a path towards incorporation into the Nanocraft