Design and Simulation of Self-Drilling Interface Materials Based on Shape Memory Alloy

Shape memory alloys (SMAs) activated by heat are suitable for compact actuators and small-scale mechanical systems. In this study, we present a self-drilling interface based on a bidirectional SMA design. The system uses two SMA torsion springs, a cylindrical housing, and internal threads to produce rotational and linear motion during heating and cooling. It can drill into soft materials without external tools or precise positioning. Tests show that the interface delivers a peak torque of 0.19 N·m and keeps the axial positioning error within ±0.03 mm over repeated cycles. This design simplifies assembly in narrow or enclosed environments. Compared with traditional fastening tools, the SMA interface offers a smaller size and easier installation. However, its long-term performance under thermal and mechanical stress still needs further investigation.