Some tech products lead their category; others create one of their own. The SANDISK® Extreme Fit USB-C
“Making something ‘simple’ is never easy,” says Sumukh Ontimitta, Senior Packaging Engineer at Sandisk, whose team first proposed the idea in 2018. That principle guided engineers across mechanical, hardware, packaging, and industrial design teams to build this incredibly compact 1TB¹ device.
Building the Smallest
The tech world has embraced USB-C. This compact connector has enabled thinner laptops, faster speeds, and universal compatibility—from notebooks to smartphones.
For Sandisk, the shift meant bringing its popular “plug-and-stay” category into a new era. However, the transition posed a major challenge, according to Sridhar Nara, Director of Consumer Product Management at Sandisk.
“With USB-A, the connector was large enough to house the memory technology inside it,” Nara explained. “USB-C connectors, however, are a different story—they’re so small that the memory has to sit outside the connector.”
Once the memory moves outside the port, durability becomes a critical concern. How do you prevent such a small device from breaking or losing electrical integrity with daily use?
According to Nara, the answer wasn’t just shrinking components—it was rethinking how they are assembled.
A Vertical Shift
Flash drives, memory cards, external drives—most USB accessories connect through a horizontal alignment, where two flat surfaces meet in parallel. An entire ecosystem has grown around this convention.
But if you want a small device to stay plugged into your laptop while you move, having something protruding from the USB port is a recipe for disaster.
The team’s first major breakthrough was breaking convention by mounting the USB-C connector perpendicular to the System-in-Package (SiP), the brain of the device.
Since no existing solution was available, engineers devised an innovative workaround using a tiny intermediate printed circuit board (PCB). This PCB interface routed signals between the connector and the SiP while reinforcing the extremely small and fragile vertical connection.
“This is the smallest SiP we’ve ever built, and it’s the first time we’ve created a vertical Type-C connector,” said Deepesh Singh, Principal Systems Design Engineer at Sandisk and product development lead.
The challenge, he noted, was greater than expected. A perpendicular connection is like balancing a piece of chalk on its tip—maintaining reliable contact is difficult. The joint must withstand impacts, vibrations, and thousands of insertions without developing microcracks or fatigue-related deformation.
“We built several prototypes, but they kept breaking,” Singh recalled. “But there was a willingness to take risks, trust in the team, and the confidence to keep going.”
Achieving Structural Integrity
Bridging the gap between an industrial design concept and a production-ready CAD mechanical model introduced a new layer of complexity.
Bringing the product to market required extensive thermal and multi-structural simulations, detailed engineering calculations, process innovations, and repeated prototyping. With each cycle, teams refined performance, improved manufacturability, and pursued long-term durability.
As the device shrank, reliability became the dominant challenge. Even minimal vibration could translate into significant stress on the SiP. The teams needed a way to securely lock the structure in place.
“We started experimenting with epoxy injection to bond the internal assembly to the enclosure,” said Vinay Kamagoud, Mechanical Design Engineering Manager at Sandisk. “But going from something that works once to something that works a million times requires a mass-production mindset.”
Epoxy starts as a semi-liquid and hardens over time. Without precise flow control—down to fractions of a millimeter—it can seep into sensitive components and compromise performance and reliability. To prevent this, the team developed new tooling, implemented strict process controls, and relied heavily on simulation.
“Achieving the smallest form factor to date introduced significant challenges in both strength and thermal dissipation,” Kamagoud added. “In the end, it all came down to selecting the right materials.”
Those choices impacted everything—from enclosure strategy and electromagnetic interference control to heat dissipation and structural rigidity.
To bring it all together, the team turned to ultrasonic welding. This method not only preserved the compact size but also created a clean, seamless exterior while delivering the mechanical strength needed at scale. Ultimately, they achieved the perfect balance between aesthetics, reliability, and manufacturability.
An Iconic Design
There’s a kind of magic when a product feels simple—and the SANDISK Extreme Fit USB-C was designed to achieve exactly that. Behind the scenes, however, that simplicity is the result of meticulous design and rigorous groundwork.
Using 3D-printed prototypes, the team tested the connector across hundreds of different laptops to determine the ideal angle. Regardless of brand or model, the drive needed to remain unobtrusive—without tilting the laptop or acting as a “stand.”
The team also pushed capacity and performance to 1TB¹ and 400 MB/s². The device had to be small in size, but not in power. Ultimately, it was the team’s insistence on visual design that made the Extreme Fit unique.
“This was one of the most challenging products I’ve ever designed,” said Adrian Karaan, Industrial Designer at Sandisk and creator of the drive’s artwork. “It was such a small canvas… How do you make something that tiny unique? How do you make it stand out?”
Karaan’s research took him back to the core of flash storage: silicon. He began mapping atoms, rings, and electrons, gradually refining his sketches into something conceptual.
“At first glance, people aren’t sure what they’re looking at—it’s intentionally abstract,” Karaan said. “But when they look closer, they can see a visualization of the atom, and I love how that connects to the technology inside.”
By carving a small window into the enclosure and sealing it with a thin, rounded lens, the team created a striking visual effect. As light moves across the surface, the iridescent design appears to shift—some users have even mistaken it for a tiny display.
“That’s exactly the effect we were aiming for,” Karaan added.
Designing the Future
The SANDISK Extreme Fit USB-C is the result of collaboration among hundreds of contributors across packaging, systems, mechanical engineering, and industrial design. It’s a simple object built through complex teamwork.
For Sumukh Ontimitta, that philosophy of simplicity has come full circle with the product’s launch.
“Simplicity was the guiding philosophy for both the team and the product journey,” he concluded. “Every decision, every constraint, multiple patent filings, and countless late-night discussions. We had to master the fundamentals and anticipate every issue. Special recognition also goes to the factory—they never deviated from the plan.”
Now, holding the tiny device in his hand, he can finally celebrate a design with purpose.
“It’s not overdesigned,” he said. “There’s nothing extra the user doesn’t want. It’s storage without complications.”
That restraint has resonated.
According to Sridhar Nara, early user feedback has been overwhelmingly positive. Sandisk’s commercial partners are enthusiastic, and several companies have already reached out to explore integrating the SANDISK Extreme Fit USB-C into their own products.
“We wanted to create something people would love,” Nara said, “and they love that Sandisk was able to innovate.”