OpenSTM
A 300 USD(2000 CNY) cost scanning tunneling microscope(STM).
This project is an open-source, low-cost STM. The system operates at ±15 V(maximum) and integrates a tip-approach algorithm, enabling the STM to establish a tunneling current within one minute. It is particularly suitable for educational use. The pictures below show the HOPG sample scanned by OpenSTM.
University of Chinese Academy of Sciences
Wuyi University