Optimized interconnect technologies address the demands of high-performance applications.
By Jessica Knight, VP of Sales Americas at Harwin.
Examine almost any modern system and you’ll see it has been designed with the majority, if not all, SWaP-C (size, weight, power, cost) elements in mind. The Innovation of COTS connectors optimized for SWaP-C criteria have enabled them to be implemented across an ever- growing range of applications, even those facing extremely challenging environments such as UAVs and satellites.
SWaP-C criteria most obviously affect the design of consumer devices such as phones. But it’s not just these portable, space-constrained systems that need to be optimized for SWaP-C. Even systems that operate in extreme environmental conditions are beholden to some or all of these elements.
An electric vehicle, especially from a luxury brand, might have fewer constraints on size and cost, but range anxiety is a key factor slowing the adoption of EVs. And since F=ma still holds true, every non- essential gram and every non-avoidable point of resistance in the system needs to be eliminated. Extra weight (especially if poorly distributed) can also affect handling, reduce acceleration, and require the use of stronger, more costly, and (ironically) weightier components, such as suspension.
Facing similar pressures is the commercial aerospace sector, which operates on the tightest of budgets. Not only does weight need to be reduced to better manage fuel usage but—to remain profitable—jets developed for commercial operators also need to deliver aerospace- level performance and reliability at commercial off-the-shelf (COTS) prices.
And elsewhere in aerospace, tactical drones used by the military are required to fly up to 160km. High-altitude long-endurance (HALE) surveillance drones go far further. Their nature (needing to be undetectable, fast, and manoeuvrable) means they need not only the ability to function reliably in sub-zero and low-pressure atmospheric conditions, but also to be as small and lightweight as possible.
Finally, let’s look at an extreme example in the form of satellites. Here, the operating conditions, coupled with the cost of repair, means designers care less about component cost than they do electromagnetic interference (EMI) shielding and operational temperature range. Their zero-gravity operating environment means weight won’t affect the functioning of the satellite, but SWaP-C still plays a crucial role. Not only do satellites operate with exceptionally tight power budgets (power comes only from the solar cells and the systems need to remain operational when entering the earth’s shadow), but excess weight results in vastly more costly launches.
In 2021, for example, it would have cost $66k to launch a 1-liter bottle of water into low-earth orbit (LEO). Competition and micro-launch vehicles have enabled prices to fall, but—even with leading micro-launcher Rocket Lab—that bottle would still cost circa $10k today. So, every gram matters.
In short, regardless of sector, OEMs and engineers are under immense pressure to deliver high performance and reliability while adhering to SWaP-C criteria.
Given that electromechanical components, connectors, and the associated cable assemblies often represent the largest and heaviest items on the board, the careful selection of each of these components can significantly impact the S, W, and C elements of SWaP-C and—to some extent—the P element as well.
Innovations in interconnect for SWaP-C
A growing number of interconnect products are now being designed with SWaP-C in mind. For these, the latest developments in materials science are being employed, as well as the use of alternative layouts, to enable lighter and/or slimmer interconnects that have smaller pitches and better electrical conductance, while still meeting the extreme demands of applications such as aerospace or the cost demands of consumer devices.
The use of advanced materials—from metal alloys to reinforced composites and the development of lightweight thermoplastics— coupled with new design techniques are allowing the development of smaller, lighter housings that deliver the same performance.
Conductive materials are also chosen to reduce contact resistance. For example, beryllium copper is often selected for its high conductivity combined with reliable spring forces for durable mating performance across a wide range of temperatures. Thin film coatings of gold or other conductive metals increase the electrical conductivity and prevent corrosion with minimal weight addition.
Design layouts are also evolving to make better use of space limitations. These layouts range from single-row vs. double-row connectors and angled (vertical-to-vertical / vertical- to-horizontal) connectors, to the integration of signal and power to reduce component count, size, and weight, as well as further simplifying the design.
Each company’s range is therefore growing in diversity, with SWaP-C- optimized COTS connectors also being designed to meet the harshest of conditions and remove the trade-offs that might otherwise be faced by engineers choosing between weight and ruggedness. If we return to the satellite example above, engineers can now source from a growing variety of compact, fine pitch, and lightweight COTS connectors that are rated for the vibration, EMI protection, shock, temperature extremes, and outgassing performance associated with satellite launches and operation in a vacuum.
Harwin’s Gecko MT is its smallest and lightest range of connectors. They have a pitch of just 1.25mm, use ultra-lightweight thermoplastic materials, and are rated to meet even the extreme vibration, shock, temperature, and outgassing requirements of a satellite.
Support and tools for SWaP-C optimization
In addition to advanced products, reputable suppliers are advancing their offering to engineers for SWaP- C-optimized technologies by providing a range of tools and support. These resources assist in several ways; for example, by speeding the identification, selection, and prototyping of connector applications.
Vendors will also provide comprehensive documentation to cover everything from product specifications to test report summaries and from product training to tooling instructions. Additionally, downloadable CAD models and extensive engineering services that encompass everything from cable assembly to rapid prototyping are playing a crucial role.
Future evolutions
Like all industries, connector developers will continue to evolve their portfolios to better meet SWaP-C challenges through advances in materials science coupled with layout evolutions. These will deliver improvements in size, weight, and power while keeping costs under control.
As we move forward, the importance of strategic partnerships with suppliers who can provide cutting-edge SWaP-C-optimized solutions will only grow. And these partnerships will prove vital as engineers strive to meet the ever-increasing demands of modern applications, regardless of whether they are designing an industrial robot or an electric vehicle.
As is the case now, electronic componentry— including connectors and associated cables—will continue to make up a sizable proportion of the weight, size, and cost of virtually every electronic system. By taking advantage of the evolutions occurring in interconnect design, system engineers can ensure their applications are not only efficient and reliable, but also cost- effective and sustainable, even as we continue to demand higher performance in smaller, lighter, and more power-efficient packages.