A key sustainability challenge is to reduce carbon footprint, requiring efficient energy, raw materials, and resource use in manufacturing. Mechatronic systems, which integrate mechanics, actuation, electronics, control, and information technology, are crucial for energy and material conversion. The future of mechatronics lies in using Cyber-Physical Systems (CPS) to run advanced simulation models online, creating a Digital Twin (DT) that mirrors the physical asset. This enables real-time data exchange, offering opportunities to enhance sustainability. The goal of this research project is to realize a DT for mechatronics systems which tracks sustainability metrics such as product quality, material waste, energy efficiency, and remaining useful lifetime. It enables to take corrective actions through adaptive control, condition monitoring, predictive maintenance, and circularity, which optimizes performance, extends lifetime, and enable component reuse or recycling.