A Miniature Self-Decoupled Multiaxis Force Sensor via 3D Orthogonal Configuration

Multiaxis force sensors can provide crucial physical contact information for intelligent robots, surgical tools, biomedical instruments, and teleoperation systems. In particular, miniature multiaxis force sensors can be easily integrated into scenarios with limited dimensions. In this paper, we present a miniature self-decoupled multiaxis force sensor (SD-MFS) that utilizes disk-shaped coils in a 3D orthogonal configuration to detect the multiaxis movements of the conductive film based on the eddy-current effect. Benefiting from the 3D orthogonal configuration, the SD-MFS has a self-decoupled multiaxis force sensing output. By adopting the folding mechanism in the electronics design, a signal conditioning circuit is also embedded in the inner frame. The fully integrated sensor prototype has an overall dimension of only $10\times 10\times 10\text{mm}^{3}$. The prototype achieved a force measurement resolution of 0.3 mN in $x-$ and $y-$ axes, 1.9 mN in the z-axis, with a low cross-talk of 2.5% and 1.6% in the x- and $y-$ axes. The SD-MFS shows promise for being readily implemented in application systems ranging from robotic hands to biomedical instruments.