Learning Dexterous Manipulation: Hands, Simulators, Training, and Evaluation
Organizations: Independent Researcher
Abstract
A dexterous hand can change an object's pose without setting it down. This survey covers 113 learning-based methods that attempt it, the hands they run on, the simulators they train in, and how they report results. The field has largely converged on one recipe: reinforcement learning on privileged state in a GPU simulator, distilled into a vision-only student for transfer to hardware. Almost half the corpus trains that way, nearly all of it in one simulator, whose own successors are barely used. A second and faster-growing branch learns from teleoperated demonstration instead, through vision-language-action models, diffusion policies, and systems whose contribution is the collection rig itself. Published work has tripled since 2022. Grasping remains the largest task family and bimanual coordination the fastest-rising, and almost every experiment runs on one of four hands. What the survey adds comes from reading released code and vendor specifications beside the papers. Eight hands that can be bought or built from published designs appear in no method paper here. Where the depth a hand sinks into the object it holds is reported at all, it is not measured in the physics that produced the motion. Section VII proposes a protocol for the unreported quantities; the body gives the counts behind every claim above.
Figures & tables
| task family | what is held | what moves | what gravity does | what counts as failure | shortest success criterion as stated |
|---|---|---|---|---|---|
| In-hand reorientation | one rigid object, held by the fingers for the whole episode | the object’s orientation in the palm frame, while contacts break and remake | a disturbance whose direction is set by hand orientation, and a load to counteract with the palm down, [ 16 ] | the object leaves the hand, e.g. the fall reset at goal distance 0.24 m in [ 14 ] | orientation error below a stated tolerance under a stated stopping rule, 0.4 rad in [ 2 ] and [ 14 ] , 0.1 rad in [ 15 ] |
| Grasping | nothing at the start, the object rests on a support | the hand closes, then the object is lifted clear | the test itself, since the grasp exists to resist it | no lift, or a drop inside the hold window | a stated lift height held for a stated duration, 10 cm for 20 s in [ 10 ] , 10 cm to episode end in [ 47 ] , 0.5 s in [ 11 ] |
| Functional and tool use | a tool, held in the pose its function requires rather than the most stable one | the tool’s own joint, or the tool acting on a second object | secondary, the function dominates | a stable grasp in the wrong place, [ 13 ] | no agreed criterion. Criteria range from never dropping the object, [ 13 ] , to a four-point rubric, [ 48 ] . The one mechanical threshold is holding the tool joint past a commanded angle for the episode, [ 49 ] |
| Tracking a human reference | whatever the human held in the captured clip | hand and object follow a recorded trajectory under physics | full, and the reference never obeyed it, so the reference is not dynamically feasible | per-frame error leaves the band, or the object drops | all stated per-frame errors below threshold for the whole clip, 30 deg and 3 cm and 8 cm joint and 6 cm fingertip in [ 17 ] . Thresholds are not comparable across papers, and DexMachina [ 18 ] calls the results “highly sensitive to the threshold values” |
| Bimanual coordination | one object by two hands, or one object per hand | both hands, the object, and the relative pose of the hands | can be carried by one hand while the other acts, [ 40 ] | the object drops, the arms collide, or the hands work against each other | no agreed criterion. Task-specific thresholds dominate, e.g. 0.035 m block-to-cup distance in [ 40 ] . The one criterion with a physical-plausibility gate is 2.0 s of hold with total penetration under 1.5 mm, [ 41 ] |
| Handover and in-hand transfer | by the giver at the start, by the receiver at the end | the object crosses between hands, released only after it is regained | unopposed during the exchange, and total in a thrown transfer, [ 19 ] | a drop at the moment of release, and the catcher’s grasp phase, [ 19 ] Sec. 5.4 | the receiver holds the object and moves it clear, more than 10 cm from the first hand in [ 50 ] , or holds it to episode end in [ 42 ] |
| method | conf. | repository | file, linked at the revision read | what the paper prints | what that file contains |
|---|---|---|---|---|---|
| PDDM [ 108 ] | high | google-research/pddm | cube_env.py _get_obs | observation dimension 46 for in-hand reorientation, Table 2 | the six fields _get_obs concatenates sum to 39 on the code’s own inline comments |
| DeXtreme [ 14 ] | high | isaac-sim/IsaacGymEnvs | AllegroHandDextremeADR.yaml actionDeltaPenaltyScale | action-delta penalty weight -0.25, Table 2 | actionDeltaPenaltyScale: -0.2 , and -0.01 in the ManualDR yaml beside it |
| Visual Dexterity [ 16 ] | high | Improbable-AI/dexenv | dclaw.yaml alg.num_envs | 32,000 teacher training environments, Table S1 | num_envs: 8000 , and 16384 in the parent hand_default.yaml |
| DexPBT [ 110 ] | high | NVIDIA-Omniverse/IsaacGymEnvs | allegro_kuka_base.py compute_kuka_reward | four staged reward terms, Sec. III-C | eight summed components, hand_delta_penalty multiplied by 0 with the comment currently disabled |
| PhysHOI [ 143 ] | high | wyhuai/PhysHOI | physhoi.py compute_humanoid_reward | object-rotation weights 0.1 and 0.01 for GRAB, Table 4 | eor and eorv set to torch.zeros_like(ep) , the computation commented out on the same lines |
| UniDexGrasp [ 151 ] | high | PKU-EPIC/UniDexGrasp | shadow_hand_grasp.py compute_hand_reward, goal_cond branch | seven named weights from 0.1 to 10, Table 7 | a torch.where cascade on literals -0.5, -1.0, 0.9, 0.1, 0.2, none of the seven present |
| axis | what is measured | minimum trials | reported with it |
|---|---|---|---|
| Task success | fraction of episodes meeting a criterion written before the run, and a graded rubric score in | 100 real and 200 sim per policy, task and condition for an absolute rate at a 10-point interval; a comparison alone needs 57 matched pairs per arm | raw counts, the criterion verbatim, the rubric, the initial-condition protocol, and an interval whose kind is named |
| Robustness | success under each perturbation axis, and the ratio to the unperturbed anchor | 40 per axis per policy to rank the axes; 101 per axis and 101 at the anchor before any claim that a named axis hurt | both absolute rates with their Wilson intervals, the axis ranges, and the ratio without an interval unless the certifying count was run |
| Unseen objects | mean over held-out objects of per-object success | 20 objects at 5 trials to screen; 93 objects for a 10-point claim | the object list, the per-object rates, a bootstrap interval over objects, and the within-object trial count |
| Physical plausibility | maximum and mean hand-object penetration depth per rollout, and the fraction of frames above 2 mm | 100 rollouts, simulation only | an interval over rollouts, the sample density, the threshold, the solver’s depenetration settings, and at least one rendered rollout |
| Sample and wall-clock cost | environment steps and wall-clock to the checkpoint that produced the headline number | 3 training seeds | the range over seeds, and the statement that 3 seeds is a range and not an interval |
| Real-robot transfer | paired real and simulated outcomes on matched initial conditions, their correlation, and the rectifier variance against the real variance | the 100 real trials paired to 100 sim; about 457 pairs to separate two correlations 0.1 apart | the correlation with its Fisher-z interval, the variance ratio with its bootstrap interval, and which decision the count supports |
Appendix figures & tables4 assets
Supplementary material from the paper’s appendix.
Appendix
| hand | maker | DoF | act. DoF | actuation | mass g | force N | force kind | tactile | price USD | open HW | status | uses |
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Shadow Dexterous Hand [ 51 ] | Shadow Robot Co. | 24 | 20 | tendon | 4 300 | – | – | optional | – | no | sold | 21 |
| Proception ProHand 1.0 [ 87 ] | Proception Inc | 22 | – | tendon | – | – | – | unstated | – | no | sold | 0 |
| SharpaWave 22-DoF [ 80 ] | Sharpa Robotics | 22 | 22 | – | 1 300 | 20 / 12 | grip | unstated | – | no | sold | 6 |
| BiDexHand [ 59 ] | Northwestern Univ. | 21 | 16 | tendon | – | 2.14 | fingertip normal | none | – | yes | open-source | 0 |
| Ruka-v2 [ 57 ] | NYU and NYU Shanghai | 20 | 16 | tendon | – | – | – | optional | 1 500 | yes | open-source | 0 |
| TESOLLO DG-5F [ 86 ] | Tesollo Inc. | 20 | 20 | direct drive | 1 763 | – | – | none | – | no | sold | 0 |
| hand | maker | DoF | act. DoF | actuation | mass g | force N | force kind | tactile | price USD | open HW | status | uses | claim date | evidence |
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Clone Robotics [ 78 ] | Clone Robotics | 27 | – | fluidic muscle | <910 | – | – | array | – | no | internal-only | 0 | 2025-11-24 | video |
| 1X NEO [ 76 ] | 1X Tech. | 25 | 25 | tendon | – | 45 | vendor, no protocol | unstated | – | no | announced | 0 | 2026-07-09 | datasheet |
| LEAP Hand V2 [ 187 ] | CMU | 21 | 17 | tendon | – | – | – | none | 3 000 | yes | announced | 2 | undated | datasheet |
| Sanctuary AI Phoenix [ 188 ] | Sanctuary AI | 21 | – | fluidic muscle | – | – | – | unstated | – | no | internal-only | 0 | 2024-12-17 | press |
| ILDA hand [ 55 ] | Korea Univ. | 20 | 15 | linkage | 1 100 | 34 | fingertip normal | array | – | no | prototype | 0 | 2021-11-05 | datasheet |
| Pisa/IIT SoftHand [ 54 ] | Centro E. Piaggio, Univ. Pisa and IIT | 19 | 1 | tendon | – | – | – | none | – | no | prototype | 0 | 2014 | datasheet |
| engine | contact model | solver | diff. | GPU | dt (s) | penetration exposed | hands |
|---|---|---|---|---|---|---|---|
| Brax [ 192 ] | convex relaxation | explicit/spring | yes | yes | – | no | 1 |
| ComFree-Sim [ 96 ] | complementarity-free | closed form | – | yes | 0.002 | yes | – |
| Dojo [ 95 ] | hard NCP | interior point | yes | no | – | yes | – |
| Genesis [ 99 ] | soft | Newton | yes | yes | – | – | 1 |
| Isaac Gym [ 92 ] | convex relaxation | PGS | no | yes | 0.008333 | no | 3 |
| Isaac Lab [ 97 ] | rigid, model unstated | Gauss-Seidel | no | yes | – | no | 4 |
| survey | yr | dexterous scope | taxonomy | bimanual | hardware | evaluation | gaps named |
|---|---|---|---|---|---|---|---|
| Surveys of the field | |||||||
| Zhao et al. [ 202 ] | 2026 | ||||||
| An et al. [ 198 ] | 2025 | ||||||
| Bai et al. [ 36 ] | 2025 | ||||||
| Welte et al. [ 199 ] | 2025 | ||||||
| Firoozi et al. [ 201 ] | 2023 | ||||||
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