RoboPhysics LaboratoryPolitecnico di Bari
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Soft grippers with electroactive contacts

Electroadhesion soft grippers and suction cups
In collaboration with the Soft Transducers Laboratory (LMTS), EPFL
1.5 kg
payload of an electroadhesion suction cup
1.5 W
power to hold it, with no compressed air
<300 ms
to release, by changing the peeling angle

The principle

Electroadhesion grippers hold objects with electrostatic forces. A thin, soft membrane carries interdigitated electrodes: when a voltage is applied, the electric field reaches into the object and pulls the membrane onto its surface. Because the membrane is soft, it conforms to the object at the scale of its roughness, and the adhesion is switched on and off by an electrical signal.

The result is a gripper that grasps without squeezing — from cherry tomatoes to jars — silently, with low power and no vacuum infrastructure. Making it practical required understanding the contact mechanics behind it: how adhesion depends on the peeling angle, how fingers zip onto curved objects, and how a membrane can combine electroadhesion with suction.

An electroadhesion suction cup holding a pipe by its bowl, with the words “Ceci n’est pas une suction cup”
Ceci n’est pas une suction cup: an electroadhesion suction cup holding a pipe, after Magritte. Caruso, Shea, Cacucciolo. Advanced Materials 2025

Results

Advanced Materials · 2025 · with EPFL-LMTS

Electroadhesion suction cups

F. Caruso, H. Shea, V. Cacucciolo

Suction cups are the light bulbs of robotics: simple and reliable, but energy-hungry and dependent on a bulky, noisy vacuum infrastructure. Electroadhesion suction cups are soft, silent, monolithic and fully electric. The membrane zips onto the object, and as it stretches during lifting it forms a passive vacuum inside its conical chamber. With a power consumption of only 1.5 W they grasp flat and curved objects, smooth or rough, holding payloads up to 1.5 kg.

Electroadhesion suction cup lifting a grapefruit, its electroadhesive membrane, and the approach, zipping and lifting phases
The suction cup and its membrane, 43 mm across: silver-ink electrodes embedded in stretchable silicone. With the voltage on the membrane zips onto the surface, and lifting it creates a passive vacuum. Caruso, Shea, Cacucciolo. Advanced Materials 2025
Electroadhesion suction cups in action. Caruso, Shea, Cacucciolo. Advanced Materials 2025

Turning the voltage off and opening a small valve lets air back into the chamber: the object is released in a fraction of a second. Mounted on a robot arm, the suction cups pick fruit, soft pouches, jars and packaged food.

Diagrams and photos of the approach, pick, lift and release of a grapefruit
Approach, pick, hold and release of a grapefruit: picking in less than 0.3 s, release in less than 0.1 s. Caruso, Shea, Cacucciolo. Advanced Materials 2025
A robot arm with an electroadhesion suction cup moving groceries from one box to another
Mounted on a robot arm, the suction cup moves a can, a bag of biscuits, a pouch, a yogurt pack, a jar and a tray of beans from one box to another. Caruso, Shea, Cacucciolo. Advanced Materials 2025
Open-access paper
Extreme Mechanics Letters · 2023

Electroadhesion zipping with soft grippers on curved objects

M. Mastrangelo, F. Caruso, G. Carbone, V. Cacucciolo

Adding actuators to close soft fingers stiffens them, and stiffer fingers conform less and adhere less. With the right materials and geometry, electroadhesion alone can drive a soft finger to zip around an object. The phenomenon is governed by two voltage thresholds — one below which nothing happens, one above which the finger fully collapses on the object — and, unlike electroadhesion forces, scales with V²/d rather than V²/d². Thin fingers wrap objects of different materials with angles up to 90°, pointing to grippers that lift objects more than 1000 times their own weight.

Electroadhesive tape zipping onto a curved substrate at increasing voltage, wrapping angle versus voltage, and fingers zipping around a grapefruit
From no zip to full zip as the voltage rises: model and experiments, and fingers zipping around a grapefruit. Mastrangelo, Caruso, Carbone, Cacucciolo. Extreme Mechanics Letters 2023
Open-access paper
Extreme Mechanics Letters · 2022 · with EPFL-LMTS

Peeling in electroadhesion soft grippers

V. Cacucciolo, H. Shea, G. Carbone

Two problems held electroadhesion back: the adhesion force can vary more than 1000 times with the angle between tape and object, and release is slow because of residual adhesion. Simple peeling models predict a force from under 1 mN to over 1 N as the angle goes from 90° to 0°. A gripper with motorized fingers puts this to use: it grasps at 0°, picking up anything from a 10 g cherry tomato to a 600 g mango, and releases at more than 30°, reliably and in under 300 ms.

Electroadhesion tape peeling model, force versus angle, and a gripper grasping and releasing a tomato
Peeling force versus angle, and the gripper approaching, grasping and releasing a tomato. Cacucciolo, Shea, Carbone. Extreme Mechanics Letters 2022
The gripper grasping delicate fruit without damaging it. Cacucciolo, Shea, Carbone. Extreme Mechanics Letters 2022
Open-access paper

Project HARTU (2023–2025)

HARTU — Handling with AI-enhanced Robotic Technologies for flexible manufacturing — was an industry-driven Horizon Europe project on the three stages of handling parts: grasping, assembly and release. One of its four technical goals was to develop versatile and dexterous soft grippers with electroactive fingertips, the contribution of Politecnico di Bari and OmniGrasp. The technologies were deployed in five industrial scenarios: four manufacturing lines — automotive, household appliances, hand tools and food processing — and one in logistics. Electroadhesion suction cups and electroadhesion zipping are among the project's published results.

HARTU: objectives, expected results and use cases. Video: HARTU project.
How to pick (almost) anything: the first HARTU webinar, on soft grippers, hosted by OmniGrasp and Politecnico di Bari. Video: HARTU project.

Spin-off: OmniGrasp

OmniGrasp, the laboratory's spin-off, creates electroactive soft robots to solve automation with difficult objects: food, textiles and biomedical products. Building on the results of HARTU, where the electroadhesion technology was demonstrated at TRL 4, OmniGrasp is now taking electroadhesion suction cups to industrial pilots in packaging, automotive assembly and logistics with the EIC Transition project EASIERGrasp (2026–2029).

Pick and place of an orange, an apple and a saline pouch. Video: OmniGrasp.
From a mushroom to an artichoke: soft fingers that conform to the object. Video: OmniGrasp.
Food, plastic, metal: objects of different sizes, shapes and materials. Video: OmniGrasp.
Packing a shopping cart. Video: OmniGrasp.
Visit OmniGrasp

Team

Publications

  1. F. Caruso, H. Shea, V. Cacucciolo. Electroadhesion suction cups. Advanced Materials 37, 2420231 (2025)Open access
  2. M. Mastrangelo, F. Caruso, G. Carbone, V. Cacucciolo. Electroadhesion zipping with soft grippers on curved objects. Extreme Mechanics Letters 61, 101999 (2023)Open access
  3. M. Mastrangelo, V. Cacucciolo. High-force soft grippers with electroadhesion on curved objects. IEEE 5th International Conference on Soft Robotics (RoboSoft) (2022)DOI
  4. V. Cacucciolo, H. Shea, G. Carbone. Peeling in electroadhesion soft grippers. Extreme Mechanics Letters 50, 101529 (2022)Open access