Microfabrication of cooling arm for fusion energy source application

The cooling arm plays an important role in the production process of fusion energy. The structure is designed with 16 fingers and is simulated by the finite-element method. The (111) crystal orientation silicon is deployed to fabricate a cooling arm, because of its isotropic Young´s modulus. It can make the fingers generate a uniform force. The silicon also has a large thermal conductivity of 2400 W/mK measured by a Gifford-McMahon cooler, which contributes to heat transfer. The cooling arm is fabricated by the microfabrication process, and it has a high sidewall vertical degree of 90 ± 0.5° measured by scanning electron microscopy. The mechanical testing result shows that the maximum stress of the clamping arm was 0.209 GPa when it was in gripping state. The maximum stress is far smaller than the yield strength of 7 GPa of silicon material.