Soft Gripper for Dried Fruit Handling: Apple Slice Gripping Case

Automating the handling of dried fruit can be more complicated than it looks.Unlike standardized industrial parts, dried fruit varies naturally in size, shape, thickness, and softness. Some dried apple slices are relatively firm, while others are softer and more flexible. This variation can make it difficult to find a gripping method that works consistently across different pieces.In this application, a soft robotic gripper was tested for picking and handling dried apple slices, with different gripper configurations evaluated to find a more suitable gripping approach.

The Gripping Challenges of Dried Apple Slices

Different Sizes and Irregular Shapes

Dried apple slices are naturally inconsistent. Their dimensions and shapes can vary from piece to piece, making fixed and rigid gripping solutions less adaptable.A gripper needs to accommodate these variations without requiring every piece to be precisely positioned or oriented.

Soft and Deformable Workpieces

Another consideration is the softness of the dried fruit.When a softer apple slice is compressed, it can deform under excessive gripping force. If the gripping force is too high, the deformation may also cause the workpiece to spring out of the gripper during movement.This creates a key requirement for the application:The gripper needs enough force to hold the fruit securely, but not so much force that it deforms or ejects the workpiece.

Gripping Solution: Different Soft Gripper Configurations

To find a suitable solution for different dried apple slices, two soft gripper configurations were tested.

Option 1: Two-Finger Gripper + Soft Wing

The first configuration combines a two-finger gripper with soft wings.This setup provides relatively strong gripping force and can be useful when the workpiece requires a firmer hold.However, when handling softer and more elastic dried apple slices, the higher gripping force can occasionally cause the fruit to deform and spring out during gripping or movement.This means that stronger gripping force does not necessarily result in better performance when handling soft food products.

Option 2: Two Single Fingers + Soft Wings

For softer dried apple slices, a second configuration was tested using two single fingers combined with soft wings.Compared with the two-finger configuration, this setup provides a relatively gentler gripping action.The soft wings also increase the contact area between the gripper and the dried fruit, helping distribute the gripping force more evenly.This makes the configuration better suited to soft and deformable apple slices, where excessive gripping force can lead to slipping, deformation, or unexpected ejection.During testing, the combination of two single fingers and soft wings achieved a higher gripping success rate for softer dried fruit.

Why Gripping Force Matters in Food Automation

For food handling applications, gripping performance is not simply about maximizing force.A successful gripping solution needs to balance:

• Holding force — enough to prevent the product from falling
• Compliance — allowing the gripper to adapt to irregular shapes
• Contact area — distributing pressure across the product
• Adaptability — accommodating differences in size and shape
• Gentle handling — reducing unnecessary deformation or damage

This is particularly important for natural food products, where every piece may have slightly different physical characteristics.

Dried fruit handling is just one example of where flexible gripping can be useful in food automation.Products such as dried fruit, fruit slices, snacks, and other irregular food items can present similar requirements: variable shapes, inconsistent dimensions, and different levels of softness.A soft robotic gripper can provide a more adaptable approach by conforming to different workpiece geometries and allowing the gripping configuration to be adjusted for different applications.For automated food handling, the right gripping solution should not only pick up the product—it should do so reliably, gently, and consistently.If you are working with irregular or deformable food products and are looking for a more adaptable gripping solution, a soft gripper may be worth considering for your automation system.