Choose a hand for the task, not the spec sheet
Turn “we need a dexterous hand” into requirements that a supplier or research team can actually evaluate.
Translate a manipulation task into a comparable, evidence-based shortlist.
Describe the object and the action
A hand that lifts a pen may not be able to turn it into a writing grip. A hand that holds an egg may not control contact while moving it. Start with an object set, starting conditions, intended motion and end state. Note which actions belong to the arm and which must happen inside the hand.
Separate essential capability from preference
Write down the fingers and contacts needed for the task. Consider thumb opposition, fingertip reach, passive compliance and the space around the object. Then check sensing and control: what observation would tell you that contact, slip or the desired pose has occurred? An attractive DOF count is not a substitute for that answer.
Check the complete setup
Compare the delivered assembly, including external actuators or controllers where required. Ask about mount geometry, power, communication, supported operating systems, SDK examples and calibration. A simulation model and a hardware driver solve different problems. Identify which exact hand revision each resource supports.
Make an acceptance task before asking for a quote
For an illustrative pen task, ask for a repeatable pickup and repositioning sequence across agreed starting poses. Specify what counts as a drop, a reset or operator help, and whether the trial is teleoperated or autonomous. Agree the attempt count and acceptable outcome with the supplier; there is no universal threshold suitable for every task.
Keep the shortlist explainable
Choose two or three plausible hands and mark each requirement as supported by evidence, needing a test, or currently unsupported. Compare source dates and test conditions. Use the same task brief when requesting information so the responses answer the same questions.
Worked example: from object to requirement
| Task | Capability to investigate | Evidence to request |
|---|---|---|
| Turn a pen in the palm | Contact changes and fingertip reach | Full attempts, start poses and control mode |
| Move a fragile object | Contact feedback and compliant behavior | Sensor logs plus the damage criterion |
| Place a connector | Pose accuracy and arm–hand coordination | Tolerance, fixture and repeatability setup |
| Collect demonstrations | Action mapping and synchronized observations | An anonymized episode and its schema |
Try it yourself
Your practical task
- Choose a real object and write the desired starting and ending states.
- List three essential capabilities and one integration constraint.
- Compare two hand cards and mark evidence, unknowns and required tests.
- Write the same acceptance task for both candidates.
What to produce: A one-page task brief and a two-hand evidence comparison.
Check your understanding
Original sources & next steps
NIST: grasping and manipulation measurement ↗MuJoCo Menagerie: model-specific documentation ↗Original Dexhands teaching material. Lesson and linked references reviewed 2026-09-24. Research links are not endorsements or evidence of hardware compatibility.