A low-cost approach to dimple grinding using a rotary tool

Conventional transmission electron microscopy (TEM) specimen preparation often relies on expensive commercial dimple grinders. This study evaluates a highly affordable alternative for mechanical thinning, utilizing a consumer-grade rotary tool. This represents a significant cost saving of two orders of magnitude, making TEM preparation much more accessible. The objective is to determine whether such low-cost equipment can produce high-quality samples comparable to those prepared using specialized laboratory devices. The methodology is outlined as follows: A dimple fabrication system, functionally equivalent to conventional commercial products, was developed using an inexpensive rotary tool. TEM specimens were prepared following a dimpling process performed using a standard commercial dimple grinder and the developed rotary tool system (evaluating both low-cost and ultra-low-cost methods). The resulting crystalline quality was quantitatively evaluated using convergent-beam electron diffraction (CBED) and symmetry analysis. Experimental results on single-crystal silicon demonstrate that the proposed low-cost method achieves crystalline quality comparable to the conventional approach. Furthermore, even the ultra-low-cost variation utilizing standard steel bits maintains structural integrity without introducing dislocations or stacking faults. These findings indicate that inexpensive rotary tools offer a practical, highly accessible solution for routine, high-quality TEM specimen preparation.