10-DOF Anthropomorphic Dexterous Hand

01CAD / Mechanical Design

Sculpted in SolidWorks using multi-guide boundary surfaces and lofts to package ten MG90S micro-servos into an anthropomorphic palm cavity with sub-millimeter clearances. Antagonistic tendon guides, knuckle hinge clevises, and a contoured bottom wrist case were modelled for low-friction articulation and rigid pedestal integration.

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[01/10] Front Assembly: Ten MG90S micro-servos packaged into the palm cavity — four lower servos drive base knuckle articulation, four upper servos drive intermediate links, and two dedicated servos drive the 2-DOF thumb.

02Manufacturing — Additive Fabrication & Knolling

All mechanical components — including finger phalanges, knuckle pivots, palm chassis halves, and forearm housings — were fabricated via high-resolution FDM 3D printing on an Elegoo build platform using organic tree supports. Following post-processing and brass heat-set insert installation, all mechanical components were knolled to verify assembly clearances.

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[01/08] Elegoo Build Platform: Printed components arranged with organic tree supports to minimize contact scarring on curved cosmetic surfaces and maintain roundness in hinge pin bores.

03Physical Assembly — Fast-Paced Build Progression

Mechanical integration progressed chronologically from phalanx pin press-fitting and knuckle bracket fastening to multi-tiered servo nesting in the palm skeleton. Live build recordings were processed into high-speed (1.75×–2.0×) animated GIFs to capture the entire hardware assembly workflow.

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[01/09] Distal Phalanx Hardware: Press-fitting miniature hex nuts into distal phalanx retention pockets and preparing silicone contact pads for high-friction grip.

04Manual Kinematic & Pulley Testing

Initial dry-run kinematic validation was performed by manually tensioning high-tensile braided fishing wire lines through printed pulley conduits. This verified friction-free line travel, positive joint curl, passive spring return, and non-binding thumb opposition before electrical energization.

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[01/03] Single-Digit Tendon Pull: Manually drawing high-tensile braided fishing wire through distal and intermediate pulley channels to verify finger joint curl and passive spring return.

05Electrical Wiring & Transient-Safe Power

An isolated dual XL4015 buck regulation architecture steps down 12V DC input to a transient-safe 6.0V / 10A servo bus backed by 4,700 µF low-ESR bulk capacitance to prevent logic resets during stall events. Thirty servo signal conductors and power leads are neatly bundled through internal wrist raceways to the ESP32 DevKit and PCA9685 I²C driver.

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[01/06] Forearm Electronics Stack: Heavy-gauge twisted power cabling and wrist pivot pass-through cleanly nested inside the forearm housing beneath the wrist joint.

• Actuator Power Rail6.0V Regulated DC @ 10A Continuous (Dual XL4015 Buck Modules)
• Transient Suppression4,700 µF 16V Low-ESR Bulk Capacitance on Motor Rail
• Logic ArchitectureESP32 DevKit @ 3.3V Logic, Optically/Galvanically Isolated from Motor Bus
• PWM Offloading DriverNXP PCA9685 16-Channel 12-Bit PWM Controller via I²C (400 kHz)
• PWM Carrier Frequency50 Hz (20 ms period), 0.5 ms – 2.5 ms Pulse Width Range (4096-step resolution)
• Cable ManagementInternal hollow wrist raceway, strain-relieved DC input jack, silicone non-slip base

06Finished Product — Kinematics & System Showcase

The finished 10-DOF dexterous hand mounted on its desktop pedestal combines an organic humanoid aesthetic with responsive, real-time actuation. Coordinated serial commands drive synchronized multi-finger flexion, wide knuckle splay, independent thumb circumduction, and high-stiffness power grasps.

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[01/09] Coordinated Multi-Digit Actuation: Full 10-channel benchmark executing simultaneous finger splay, flexion, and independent thumb opposition.