Load cells are the force multiplier in precision gripping applications
Behind the seemingly intuitive act of grasping an object lies a complex interplay of forces that, if measured inaccurately, can lead to catastrophic failures and significant safety risks in numerous industrial and medical applications.
From the delicate touch of a sensitive semiconductor to the immense force required to secure a heavy construction beam, accurate quantification of gripping pressure and the forces generated by the end effector is not only beneficial, but an absolute engineering requirement. The consequences of inadequate force measurement go beyond mere inefficiency and include devastating statistics regarding material damage, operational downtime, and, most critically, can lead to safety issues.
Interface load cells feature various capacities and capabilities that are fundamental to improving gripping solutions across many industries. Force measurement sensor technologies provide reliable, real-time feedback on the applied gripping force, enabling sophisticated closed-loop control systems. This level of precise measurement is critical for preventing damage to handled objects by ensuring optimal force application, validating ergonomic designs by quantifying user interaction forces, and ensuring operational safety by preventing component overstress or accidental drops.
The testing and measurement requirements for gripping applications are stringent. They require high accuracy, repeatability, low hysteresis, and robustness to ensure reliable performance in dynamic and varied operating environments.
Gripper applications for measuring sensors
Load cells, especially our mini load cells and load button load cells, are commonly integrated into various gripping applications, from surgical robotics to drone lifting devices. Other industry solutions include industrial robotics, jigs and clamps, medical devices, horticultural equipment, and general quality inspection. These types of gripping use cases are highlighted below.
Robotic End-of-Arm Tooling (EOAT)
In the automated Production and material handling, load cells mounted on robot grippers measure the force that Pick-and-place operations, Assembly and Packaging applied to the parts. This prevents over-clamping, which could damage delicate components, and ensures a secure grip for safe transfer. For example, in electronics assembly, a low-capacity load cell can precisely grip small circuit boards without causing breakage.
Industrial clamps and fixtures
It is common practice to incorporate miniature load cells into clamping mechanisms to monitor and control the holding force during machining, welding, and assembly processes. This ensures consistent clamping of parts and prevents slippage or deformation due to excessive force. For example, a high-capacity compression load cell in a vise in a CNC machining center can provide feedback to maintain optimal clamping pressure on a workpiece.
Medical and surgical tools
Load cells are increasingly being integrated into handheld surgical instruments and robotic-assisted surgery systems. Handheld instruments such as laparoscopic graspers provide surgeons with tactile feedback regarding the force applied to tissue, enabling delicate manipulation and preventing iatrogenic injury. In surgical robots, load cells on the robotic arms and end effectors provide precise force control during procedures such as tissue retraction, suturing, and organ manipulation, increasing accuracy and minimizing trauma. Due to space constraints and the need for high sensitivity, miniature S-type or knob load cells are often used in these applications. Read our application note: Force feedback in robotic surgery
Prosthetic devices
In prosthetic hands and medical gripping tools, load cells provide the user or operator with sensory feedback, enabling delicate manipulation and controlled application of force. This is critical for tasks such as holding delicate instruments during surgery or enabling a prosthetic hand to grasp objects with appropriate pressure. Miniature Type S load cells are widely used for such applications due to their compact size and ability to measure tensile and compressive forces. In this demonstration, you will see how to use our BX8 manual and the 6-axis multi-axis sensor that can measure joint forces during movement and grasping in real time.
Drones and unmanned aerial vehicles (UAVs)
Since the applications of drones and UAVs become more sophisticated, including delivery, inspection and potential personnel transport, load cells are in their gripping and Payload management systems They ensure secure attachment and controlled release of payloads and can also provide feedback on the weight distribution and stability of the carried load, improving flight safety and operational efficiency. Compact, lightweight load cells are often preferred for these weight-sensitive applications. Learn more about our solutions for Testing commercial drones and parcel delivery.
Testing and quality control
Load cells are essential for testing the grip and durability of various products, from hand tools to consumer goods. They provide quantifiable data on the force required to grip and the maximum force the grip can withstand before failure. Universal load cellsthat measure tension and compression are well suited for these test scenarios.
Agricultural systems
In automated Harvesting systems Load cells on robot grippers can detect the ripeness and fragility of fruits and vegetables and apply exactly the force needed for a secure yet gentle grip to minimize damage during harvesting.
Six exciting advantages of using interface sensor technologies
The integration of interface products into gripping devices, products, machines, tools and robotics offers several key advantages:
#1 Precise force control – Real-time force feedback allows precise control of gripping pressure, preventing damage to the objects being handled and ensuring safe handling.
#2 Improved safety – Grip force monitoring can prevent heavy or awkward objects from slipping, reducing the risk of accidents and injuries. In medical applications, it minimizes the risk of tissue damage during procedures. In drone applications, it ensures secure attachment of the payload during flight.
#3 Improved efficiency – Optimized grip force can lead to faster cycle times in automated processes and reduced material waste. In surgical robotics, it can contribute to more efficient and less invasive procedures.
#5. Quality Assurance – Consistent and controlled gripping forces in manufacturing and assembly contribute to higher product quality and fewer defects. In medical device testing, they also ensure the reliability and safety of surgical tools.
#6 Data and Traceability – Load cell data can be recorded and analyzed for process optimization, quality control, and predictive maintenance. It can provide valuable data for training and procedural analysis in surgery and contribute to better payload management strategies in drone operations.
Products for gripping and measuring technology Applications
Interface offers a wide range of load cells suitable for various gripping applications, including:
- LowProfile load cells: They are compact and versatile, ideal for applications with limited space. They offer both tension and compression measurement functions. Examples are the 1200 and 1500which are commonly used in drone payload systems.
- Miniature load cells and Load button load cellsThese small, highly sensitive sensors are perfect for integrating compact grippers and precisely measuring forces in tight spaces. They are often found in surgical instruments and miniature robot grippers. ConvexBT™ load button load cell was developed to improve off-center durability.
- S-type load cells: These cells are designed for high-precision tension and compression measurements. They are often used in gripping mechanisms and testing applications and can be adapted for larger robotic arms for surgery. S-type load cell from SSMF with fatigue properties is suitable for durability tests.
- Beam load cells: These robust sensors are ideal for higher-capacity gripping applications and can be integrated into clamping fixtures. Examples include sealed S-beam load cells for demanding environments.
- Multi-axis load cellsThese cells can measure forces in multiple directions simultaneously and provide comprehensive data for complex gripping tasks, such as advanced robotic surgery and sophisticated drone manipulation. The series 6A measures force and torque in all six axes.
- Load cells: They are used to measure the clamping force of screws. They are useful in applications where secure fastening is critical for the gripping mechanism, including ensuring the stability of drone components or surgical robot joints. The LW series is used to measure screw tension.
Engineers can develop highly effective and reliable gripping solutions for various industrial, medical, aerospace, drone, and research applications by selecting the appropriate interface load cell based on capacity, size constraints, environmental conditions, and measurement requirements.