A design rarely (if ever) begins with the connector. Yet everything needs power and signals must be communicated. Connectors often take the brunt of the mechanical and thermal forces endured by a system, so correct specification is vital, and – like any other component – they must be fit for purpose. Therefore a tiny connector produced to satisfy the needs of a consumer item will not withstand harsh environments or be suitable for critical applications that simply must not fail. How, therefore, can the designer embrace miniaturisation without compromising his system?
Two contrasting applications that illustrate this conundrum perfectly are nano-satellites and medical devices.
Miniature, nano-satellites are very popular amongst the scientific and academic communities. For example, as of January 2019, over 1000 CubeSats have been launched. Nano–satellites are small, usually weighing less than 10 kg, and in some cases a lot less. Cubesats, built to a standard format of 10x10x10cm, weigh just 1.33kg, although sometimes modules are combined. Such satellites are designed to carry one or two scientific instruments into space at a comparatively low cost. Yet even Cubesats cost around $100,000 to make and $50,000 to launch, so a simple connector failure must be avoided at all costs.
Connectors are such a critical component because not only to they carry a signal (or power), they also physically connect to parts of a system. Therefore there are mechanical stresses on the connector as well as the electrical performance to consider. In space applications, connectors must survive high levels of shock and vibration at launch, plus extremes of temperature as the satellite orbits between exposure to the sun and ‘the dark side of the Earth’. There are, of course, extremely rugged and very durable connector systems available, but many of these are heavy and bulky and quite unsuitable for space missions in miniature satellites where space and weight are at an absolute premium. So the challenge is to identify a connector system that is both robust and durable enough to survive the space environment, yet is high-performance, light and small. Ideally, of course, it will be a COTS or COTS+ part in order to keep costs low.
The challenges manufacturers and designers face in the rapidly-evolving landscape of medical devices are numerous. As devices get smaller, there are increasing issues about safety. System designers are looking for connector companies that can deliver the best interconnection systems that enable more functionality in smaller spaces, and also to higher security levels. All this while ensuring products are sterile and able to withstand aggressive cleaning solvents and potential contamination from bodily fluids.
Emerging products such as powered, intelligent surgical tables, diagnostic devices, laboratory instruments such as IRM, endoscopy and electrocardiography equipment are examples of applications that must be 100% reliable. Otherwise, a false treatment may be administered, or a condition may go undetected. With the rise in home diagnostics – with patients self-monitoring in their own home, streaming information back to a medical centre for analysis, devices need to be even more rugged and simple to use, as the patient, unlike a doctor or nurse, will have no training it the equipment’s use.
Nicomatic is a French company that specialises in producing miniature connectors for demanding applications, as well as cabling solutions and metal dome switching technology for all types of man/machine interfaces.
The company’s best-selling CMM micro connector range (Figure 1) is a 2mm pitch system that features extreme modularity with more than 20 million configurations of signal, power and coax pins from one to three rows and up to 120 pins deliverable – all on one week leadtime with low MOQ. Offering space-savings of up to 60% and weight savings of up to 50% when compared to other existing rectangular connectors with similar functionality, CMM connectors are manufactured in robust PPS material so they exhibit no humidity absorption and oxygen-free and resistant to radiation and solvents. Devices can withstand temperature cycling of between -60°C and +260°C. Due to its advanced contact technology, Nicomatic can pass more current through the connector while adhering to required defence performance standards and applications.
CMM connectors are preferred by designers of cubesats, such as Space Center within the University of Grenoble (CSUG). They are also used with flat cable CRIMPFLEX® technology in Nicomatic’s high reliability Microflex™ harness solution that can save design time and minimize costs in medical applications. Other advantages of the connector/cable solution for medical, space and other applications includes a weight reduction of up to 30% when compared to bulky cables), smaller size due to the 2mm pitch, a lower profile than discrete wires, and high reliability under vibration.
As well as the CMM connector range, Nicomatic produces 1.27mm pitch EMM connectors, DMM Micro D Mix connectors that comply with MIL-DTL-83513G, shielded composite versions and the newest, 1mm pitch product, the AMM series (Fig 2). All have been designed to maximise performance while minimising space and weight.