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Robot Grippers: Finger, Suction, Soft, and Paddle Tools Compared
Robot grippers decide which SKUs a picking robot can handle. Compare finger, suction, soft, and paddle tools, tool changers, and how to test them on your items.
6 min read
· Updated
November 2026
At a glance
The definition
A robot gripper is the tool at the end of the arm that grasps, holds, and releases items. It often decides which of your SKUs a robot can pick.
The main types
Two-finger grippers squeeze, suction grippers seal, soft grippers conform, and paddle tools slide under. Each handles some packaging well and struggles with other kinds.
How to choose
Profile your SKUs by packaging, weight, and surface, then test grippers in your own bins. Measure grasp success, drops, and damage over hundreds of picks.
Robot grippers are the end-of-arm tools that let a robot grasp, hold, and release objects, using fingers, suction, or other contact methods. In warehouse picking, the gripper often determines which items a robot can pick at all and how often it needs help, so it deserves as much testing as the arm.
When a picking robot misses, the cause is often at the end of the arm, not the arm itself. The item slipped, the suction cup could not seal on a wrinkled polybag, or the fingers could not fit between tightly packed boxes. In a warehouse with thousands of SKUs, the gripper decides which items a robot can handle at all, and how often it needs help. That is true whether the robot is a fixed cell or a mobile pick and place robot.
This guide covers the main types of robot grippers for warehouse picking, how tool changers and combined grippers extend coverage, and how to test grippers on your items. For the arms themselves, see robot arms in warehousing. For complete systems, see robotic picking systems.
Robot grippers vs. end effectors and end-of-arm tooling
End effector is the standards term for whatever is mounted at the robot's wrist. End-of-arm tooling (EOAT) is the industry term for the full assembly: the gripper plus any sensors, cameras, compliance, and quick-change hardware. Many robots use a standard mounting flange: ISO 9409-1 defines the main dimensions of the circular plate so end effectors can be exchanged and keep their orientation.
People also search for robot hand, usually meaning a multi-fingered gripper that can reposition items in its grasp. In warehouse picking, the useful question is not how human-like a gripper is, but whether it reliably picks your items. Fewer moving parts also means less to wear out.
Two-finger and multi-finger grippers
Finger grippers close on an item and hold it by friction or by wrapping around its shape. They were the most common choice in the first Amazon Picking Challenge, where 84% of teams relied on force closure, friction, or both.
Good for. Rigid items with graspable sides, such as bottles, jars, tools, and boxes with space around them, plus items suction cannot seal on, like mesh, fabric, or open-weave packaging.
Limits. Fingers need clearance on both sides, which tightly packed bins may not give. Grip force has to hold the item without crushing it, and fingertip material and texture matter as much as the mechanism.
SKU fit check
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Suction grippers
A suction or vacuum gripper seals one or more cups against the item and removes air. According to Schmalz, a suction cup's holding force is the pressure difference times the effective suction area, and it recommends a safety factor of at least 2, rising to 2.5 or more for workpieces that swivel or rotate. In the Amazon Picking Challenge analysis, the authors saw a clear trend in favor of suction, and the winning team used suction alone.
Good for. Cartons, boxed goods, flat-faced rigid packaging, and picking from the top of a cluttered bin, where the gripper only needs one exposed surface.
Limits. Porous items, mesh, loose fabric, and wrinkled film leak air. Items smaller than the cup, or heavy items with a small flat face, are hard to hold. Schmalz advises running suction trials for porous parts, and in the challenge a metal mesh pencil holder and foam balls gave suction trouble.
Questions to ask. How is vacuum generated, especially on a mobile robot, and what happens to the grip if power or air is lost mid-move?
Soft and compliant grippers
Soft grippers use flexible materials that conform to an item instead of clamping it with rigid jaws. A review of soft robotic grippers found they can grasp a wider variety of objects than rigid grippers, and groups them into three approaches: grasping by actuation, by controlled stiffness, and by controlled adhesion. That makes them worth testing on delicate or irregular items such as produce, cosmetics, and bagged goods. The same review lists open challenges in robustness, speed, sensor integration, and control, so test wear and cycle time, not just the first grasp.
Fit call
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Paddle and spatula-style tools
A paddle tool slides a flat plate under or beside an item to lift or scoop it, rather than squeezing or sealing. It helps with flat items lying on a shelf, thin items fingers cannot get around, and packaging suction cannot seal on. In the Amazon Picking Challenge, the second-place team's gripper paired suction with a spatula-like fingernail that could scoop items from underneath or grasp items flush against a shelf wall. Paddle tools need a surface to slide along and room to approach, and they may need a clamp or second contact point to keep items secure during fast moves.
Tool changers and combined grippers
No single gripper handles every SKU, so picking systems that handle many SKUs widen coverage in one of three ways:
Combined grippers. One tool carries suction and fingers, so the robot can choose per item. In the Amazon Picking Challenge, the second-place team took this route, while the third-place team put a suction cup on one arm and a grasping hand on the other and chose the tool per item.
Automatic tool changers. A master side on the robot and a tool side on each gripper lock together automatically and pass utilities such as electrical signals and air, so the robot can swap grippers without a person.
Manual quick-change. Staff swap grippers between shifts or SKU families. It is simpler and cheaper, but the gripper choice stays fixed for longer.
Each approach adds changeover time or hardware to maintain, and your task planning has to know which gripper fits which SKU. The more your item mix changes, the more gripper coverage matters. See high mix order picking automation for how SKU variety shapes the rest of the system.
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How to choose and test robot grippers
Profile your SKUs. Group items by packaging (boxes, polybags, bottles, blister cards, loose items), weight, size, fragility, and surface. Include your top movers and your worst cases.
Test in your presentation. Use the same bins, fill levels, and orientations you run in production, not items laid out on a table.
Measure what matters. Track grasp success, drops, double picks, damage, and cycle time over hundreds of picks per SKU group.
Plan for wear. Cups, fingertips, and soft fingers are consumables. Ask for replacement intervals, cost, and how long a swap takes.
Check safety. Include the end effector in your risk assessment. ANSI/A3 R15.06-2025 adds new content on end effectors for industrial robot systems.
Where Avatar fits
Avatar's robots handle picking, packing, kitting, sorting, and carting inside your existing workflows, working from existing racks and bins with no facility redesign. If you run one fixed, high-volume task on a single item type, a dedicated cell with specialized tooling may serve you better. See where Avatar works on the Avatar solutions page.
Frequently Asked Questions
What is the difference between a robot gripper and an end effector?
An end effector is anything mounted at the end of a robot arm, including grippers, welding torches, screwdrivers, and cameras. A gripper is the type of end effector that grasps and releases objects. In picking, the two terms are often used interchangeably.
When should you use a suction gripper instead of fingers?
Suction works best on items with a flat, sealed surface, such as cartons and boxed goods, and when only the top of an item is exposed in a cluttered bin. Fingers work better on porous, mesh, or fabric items and on shapes with graspable sides. Many picking systems combine both.
What is end-of-arm tooling (EOAT)?
End-of-arm tooling is the assembly mounted at a robot's wrist: the gripper plus any sensors, cameras, compliance devices, and quick-change hardware. It connects to the robot through a mounting flange, often to the ISO 9409-1 standard.
Can one robot use multiple grippers?
Yes. A robot can carry a combined gripper with suction and fingers, swap tools automatically with a tool changer, or have its gripper changed by staff between shifts. Each option trades flexibility against changeover time and hardware to maintain.
Sources
1. International Organization for Standardization (2004, confirmed 2023). ISO 9409-1:2004 Manipulating industrial robots — Mechanical interfaces — Part 1: Plates. ISO.
2. Correll, N., Bekris, K. E., Berenson, D., Brock, O., Causo, A., Hauser, K., Okada, K., Rodriguez, A., Romano, J. M., & Wurman, P. R. (2018). Analysis and Observations From the First Amazon Picking Challenge. IEEE Transactions on Automation Science and Engineering, 15(1), 172–188.
3. Schmalz (n.d.). Vacuum knowledge: Design of the Suction Cup. J. Schmalz GmbH.
4. Shintake, J., Cacucciolo, V., Floreano, D., & Shea, H. (2018). Soft Robotic Grippers. Advanced Materials, 30(29), 1707035.
5. ATI Industrial Automation (n.d.). Robotic Tool Changers. ATI Industrial Automation.
6. Association for Advancing Automation (2025). New ANSI/A3 R15.06-2025 American National Standard for Industrial Robot Safety Now Available for Purchase (September 9, 2025). A3.
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