We have developed an autonomous, energy-self-sufficient electronic tool logbook for permanently monitoring temperature-controlled tools. It is designed to operate on-site without an external power supply. The device generates the electrical energy for its operation from the process waste heat. Cables or batteries are not necessary. It continuously monitors process-critical data and events for tool and production without the need for regular interaction with the user.

The digital tool logbook is permanently installed on the tool and stores tool data and history. In addition, it continuously monitors and stores the most critical process parameters during the production process. Data such as temperature deviations, unusual accelerations, and cycle times are measured, monitored, and evaluated. Overruns of defined limit values are detected. After production, the tooling conditions and special events (e.g., shocks) are recorded during the set-up processes, transport, and storage. The recorded data is permanently stored on the device in a non-volatile memory and can be retrieved anytime. The system is designed to automatically start and stop the measurements without any user interaction.

The local user interface is robust, simple, and limited to critical information. An e-paper display constantly represents the most essential data. The device communicates with a mobile phone or tablet via Bluetooth Low Energy (BLE) for configuration and data export.

Testing the prototype on injection molding tools in the production of plastic parts shows that energy harvesting is ripe for industrial production processes. The requirements for robustness, reliability and availability for industrial manufacturing can be met.