This paper presents a novel approach for modeling
one-degree-of-freedom human metacarpophalangeal/ interpha-
langeal joints based on a teeth-guided compliant cross-four-bar
linkage. The proposed model allows developing self-adaptive
anthropomorphic fingers able to be 3D printed in a single
step without any accessories, except for simple tendon wiring
after the printing process, using basic single-material additive
manufacturing. Teeth-guided compliant cross-four-bar linkages
as finger joints not only provide monolithic fabrication without
assembly but also increase precision of anthropomorphic robot
fingers by removing nonlinear characteristics, thus reducing the
complexity of control for delicate grasping. Kinematic analysis
of the proposed compliant finger joints is detailed and nonlinear
finite element analysis results demonstrating their advantages
are reported. A two-fingered underactuated hand with teeth-
guided compliant cross-four-bar joints is also developed and
qualitative discussion on grasping is conducted.