Circular IoT: Longer lasting wireless sensor nodes for industrial applications

Abstract

With the ever increasing number of wirelessly operated connected devices, the environmental consequences that this trend brings about need to be considered. This project has been carried out to explore the possibilities for transitioning industrial IoT sensor nodes into the circular economy.

Wireless sensor nodes are battery powered instruments for monitoring processes and condition of industrial equipment. They need to endure harsh environments and are subjected to critical certification. In general, they are discarded once their internal battery depletes, meaning their embedded potential is lost.
Structuring the analysis of Edge Dynamics’ current product on circular aspects using tools such as HotSpot mapping and the Disassembly Map framework, revealed the disassembly steps and activities that inhibit circular activities such as repair, remanufacturing and recycling. These key components are responsible for a significant fraction of the product’s environmental and economic footprint, or are subjected to a high rate of replacement.

The outcome of the project is a concept sensor node featuring an optimised product architecture. The concept uses a novel way to configure the internal components as such that the key components have the top priority in disassembly. The redesigned sensor node is faster to repair, faster to assemble and disassemble and houses less components. Moreover, the product is made up of less materials and better fits recycling processes as no materials are mixed.
On a system level, circular strategies such as repair and remanufacturing can considerably reduce the environmental impact of the sensor nodes, as giving nodes a second or third lifespan will prevent the need to use virgin materials for the manufacturing of new products.

On a product level, the current product’s key components are sufficiently easy enough to reach and repair that a redesign will only make a significant difference in time savings, and thus costs, on a certain scale. Optimising the sensor node has not increased the embedded footprint. Reusing the circuit boards by for instance repairing sensor nodes can dramatically reduce the lifecycle footprint.
On a material level, using exclusively recycled metals and polymers in the sensor node could reduce its carbon footprint with 4,9% compared to the use of materials containing typical recycling fractions. Moreover, the effectivity of recycling processes can be improved by avoiding the use of mechanical fasteners mixed with dissimilar metals.

Besides the potential reduction of the environmental impact of wireless sensor nodes, a financial incentive is likely at hand as well. Depending on the scale of operation, significant cost reductions can be achieved by faster maintenance and repair when operating a circular business model.

Combining the efforts of each level will lead to the highest potential for sustainable sensor nodes. Edge Dynamics can take a leading role in the industry, offering circular IIoT devices.