Senior industrial design sculptor Mark Ferri’s fingertips have been critical in developing some of the most iconic sports cars of the past two decades, as well as some of the most popular vehicle lines at General Motors.

In a 17-year career at GM, he led the teams designing the exteriors and interiors of vehicles such as the Corvette Stingray, the Camaro 6, the Cadillac CTS, and the Chevy Colorado and Trailblazer. Many of these sleek looks were first refined as full-size clay concept models before they were further developed as 3D CAD models.

Ferri, now a senior industrial designer for Uber’s Advanced Technologies Group, recently shared insights on conceptual design and prototyping as a guest on Onshape founder Jon Hirschtick’s “Masters of Engineering” podcast. While the automobile industry relies heavily on sophisticated product development tools, Ferri revealed the surprisingly critical role of physical human touch.

Having your hand caress the hood, the roof, the tail lights and the doors can sometimes detect microscopic flaws better than the human eye, he said.

This idea is called cross-modal sensory perception.

Simulation software is important in automobile design, but so is old-fashioned human touch, says industrial designer Mark Ferri. (Image source:

“If you run your fingers over a piece of laminate where one side face intersects with another, and there's a 200th of an inch or a fraction of a millimeter sub-flash condition, you can feel certain things before you can see them,” Ferri told Hirschtick.

“You know how that phenomenon occurs when you eventually make a part that doesn't look exactly the way you thought it would? That's why manufacturers can’t get away from making physical prototype parts. And clay is one of the ways that you can add and subtract once you've machined,” he added.

Ferri reminisced further about how General Motors implemented cross-modal sensory perception into its automotive design processes.

“One of the things I remember learning early on was if you were physically working on a model with your dominant hand, because more stress was being put into it and it had more blood pulsing through it, it was less sensitive than your less-dominant hand. So they would ask you to run your less-dominant hand over a large surface to find where curvatures and topology would go flat or increase,” he recalled.

“When you're washing your car, you can feel the same thing,” said Ferri. “You'll run the sponge over one side, one panel, and then when you run your non-dominant hand across it, it's just a little bit more sensitive. And if you close your eyes, it even becomes more apparent.”

You can listen to Jon Hirschtick’s full conversation with Mark Ferri here, or wherever you download your favorite podcasts.

Binge Listen to the New “Masters of Engineering” Podcast

Jon Hirschtick’s new “Masters of Engineering” podcast is devoted to the backstories behind cool products, the people who develop them and how they do it. As the founder of both SOLIDWORKS and Onshape, and now PTC’s Executive Vice President, Hirschtick explores his lifetime fascination with the product development process – how ideas evolve into products with many twists and turns along the way.

The first four episodes are now available for download at BuzzsproutSpotify, and Stitcher. In addition to Ferri, here are the other product innovators to sit down with Hirschtick so far:

  • Robots That Can Touch and Feel (Dr. Bill Townsend, founder of Barrett Technology) – Barrett Technology’s humanlike robot once shook hands with Arnold Schwarzenegger, but attracting celebrity friends is not its primary talent. Barrett is a pioneer in haptic robot arms and hands, which can apply the appropriate amount of physical pressure in different situations like a human would. The technology now has medical and physical therapy applications, with the robot arm even being able to give a massage. In this episode, Bill tells Jon the secret behind his robots’ magic touch and reflects on how his engineering journey first started when he built a treehouse at age 14.

  • Pickpocket-Proof Backpacks (Sarah Giblin, founder of Riut) – Sarah Giblin is an accidental designer. While waiting to get off an airplane, she noticed a fellow passenger nervously unzip his backpack and stuff his wallet and passport in his front jeans pocket. She soon unconsciously found herself reacting the same way: “My God, is my wallet and passport still there?” In this podcast, Sarah tells Jon how she developed the RiutBag, a backpack with zippers that go flush against the wearer’s back (with no zippers on the outside), and how she navigated the product development world without any design or manufacturing background.

  • Reimagining How Machine Parts Get Made (Mitch Free, founder of ZYCI and – Mitch Free is a college dropout who partnered with Amazon’s Jeff Bezos to build, the first online marketplace bringing together product designers and manufacturers. The serial entrepreneur is now seeking to improve the way every machine part in the world gets made. He’s currently the founder and CEO of ZYCI (pronounced “ZEE-key”), a CNC-machining, plastic molding and additive manufacturing company serving the aerospace and defense industries. In this podcast, Mitch reminisces with Jon about his unusual career path from refurbishing used aircraft to figuring out how to cut Ferrium M54, one of the toughest steels ever made.

Stay tuned to this space for information on upcoming episodes!