Passive RFID Solution Sensors Detect Supply Levels

Published: October 21, 2023

Tund is offering its solution leveraging strain sensor technology from Asygn for a battery-free system that monitors content levels of drawers or containers based on weight and transmitted via RFID.

A European manufacturer is the first to pilot a new solution that leverages battery-free UHF RFID sensors to capture weight data and transmit that information to a reader. RFID-based software solutions company Tund recently released its “Never out of Stock” solution, using RFID Smart Scale sensors from Asygn. Using the system, the manufacturing company can view how many items are on its shelves or drawers without deploying cameras, tagging each item with an RFID tag, or physically counting the contents.

Tund is a German solutions provider, launched in 2019, that focuses on RFID-based solutions – for small and mid-sized companies – that go beyond simple inventory counting. The company’s goal, says Nikola Diskic, strategic business development director, is to offer sustainable and affordable technology-based solutions to companies that may have specialty requirements as well as limited budgets.” We try to bridge a gap between the small and medium-sized opportunities, and the enterprise business,” that have the funds to incorporate large or complex solutions and technologies, says Diskic.

In fact, in many cases, the kinds of companies Tund serves are not familiar with some of how technology could improve their operations or make them more efficient, he says. So, Tund offers an affordable service to digitize and automatically manage their supplies or inventory. Tund builds solutions specific to customers’ needs, manufacturers, supply chain companies, and healthcare providers. Many companies track their supplies via barcode scans or manually counting items in each container or bin. If supplies run out during production, the result can be a manufacturing shutdown. “That can be a nightmare for a manufacturer or a producer,” Diskic says.

The smart-scale solution uses RFID transmissions to power the passive sensor that then measures weight and transmits that data back to a reader.

In an application such as a warehouse asset management system, says Ivan Samyshev, Asygn’s sales manager, the goal is to be able to monitor the number of small assets in the box on the shelves in the warehouse or facility. While large or high-value assets are often tagged with RFID tags, that’s too costly for small assets. “The idea was to use an existing UHF RFID reader in a warehouse to monitor filling level with a resolution of 10 percent to plan for replenishment.”

How it Works

The system consists of individual strain scales placed underneath boxes or containers of a product or in drawers. The ranking is based on Asygn’s AS3213S strain sensor. The monitored contents could be anything from screws, spare parts, rubber gloves, or medications.

The solution is designed to evaluate the contents levels in a bin, while the strain sensor can measure weight up to about 3 kilograms. A reader and external antenna are mounted underneath the drawers or shelved containers and are connected to a power source. Asygn developed the technology in 2021 and released the prototypes last year, says Samyshev. Tund is one of the early adopters.

At intermittent intervals, the reader interrogates the RFID tags within its vicinity. The power of that interrogation wakes the sensors, and they each take a strain reading to identify the weight and, therefore, the number of supplies in the bin. The technology uses the RF power to respond to the interrogation – via an RFID signal – back to the reader, which forwards the sensor data, and RFID tag reads to Tund’s server, where software interprets the data and identifies the weight reading for each sensor.

That data is compared against pre-set thresholds to determine the weight of each RFID tag and calculate how much of the contents have been removed. The system can be set to identify the percentage of product in that container or drawer and when it reaches a minimum threshold quantity, explains Diskic. If any container reaches the pre-set minimum, an e-mail is automatically sent to the authorized party to place a reorder.

The technology can be used for more than real-time inventory updates, however. The companies using the technology can also accomplish analytics by tracking supply levels over time. “We encourage our customers to use the technology for trend analysis. In that way, a company could not only know in real time what they have onsite and when it needs to be restocked, but also what usage trends are,” Diskic says.

Companies can view anomalies over time as supplies are used and re-stocked to identify when replenishment is needed or if some parts are unnecessary because they are rarely used.

Each deployment typically will be customized since each use case has different requirements and provides its challenges, Diskic says. For instance, in an environment with metal or fluids, the RFID transmissions can be more challenging, which will require some configuration in a few cases.

Companies can use the system as a service without buying software or integrating a system with their own ERP.

Tund has created solutions to suit specialty and sensor-based requirements rather than offering essential inventory management with standard RFID tags. “We are a small provider who provides niche solutions,” he says.

While the early deployments will be in manufacturing, the system could also optimize the drug stock inventory in pharmacies to see how many medications or packages are on site and ensure that no medication is ever out of stock.

Greener Low-Cost, Technology-Focus

The company reports that a key pillar for Tund is sustainability; the company achieves a more sustainable solution by offering a passive RFID system that doesn’t require batteries. The lack of battery in solutions such as the Smart Scale means less environmental impact, Diskic argues, “You’re just not producing the waste.”

The other advantage, Tund points out, is the low cost of ownership. Because companies don’t have to acquire high-cost software, it’s more cost-effective as well as easy to implement. “We go with a bottom-up approach, not top-down – with a small proof of concept,” says Diskic. That means a company can start with a single application, such as tracking supplies through the battery-free RFID scales but could then add additional applications.

Another of Tund’s solutions consists of an LED-based RFID system known as “Pick by Light,” in which the RFID tag has a built-in LED light that is illuminated when interrogated by a reader, set to seek a specific tagged item or multiple items at once. The readers can be fixed – mounted in an area such as a storage room – or a handheld or Bluetooth-enabled RFID reader tethered to a smartphone, says Diskic.

The company also offers its RecoFID program, in which tags are used and then reused multiple times or sent back to Tund to be refurbished for reuse.

Diskic sees the program as an alternative to its competitors that sell recyclable RFID tags, “We are going one step further and strive for a circular economy,” in which tags can continue to be used. “With that, we are reducing the CO2 emission in the world, and also, we can expand the life of a label,” he says.

In the future, the company hopes to offer its solutions to pharmaceutical and retail markets and linen and laundry services.

Key Takeaways:

  • A manufacturer has begun testing a smart-scale solution from Tund, using Asygn passive RFID sensor technology to track supply levels with a battery-free system.
  • With an RFID reader, users can interrogate the RFID tag, power the sensor to capture weight data and read the response, creating a digital record of supply levels.