Countries collaborate through various mechanisms: 1. Bilateral and Multilateral Agreements: Governments establish agreements to promote joint research and development. 2. International Conferences and Workshops: Forums like the International Conference on Nanoscience and Nanotechnology provide platforms for networking and sharing research findings. 3. Joint Research Projects: Collaborative projects involving institutions from multiple countries can pool resources and expertise. 4. Student and Researcher Exchange Programs: These programs enable the exchange of knowledge and foster long-term international collaborations.