Featured Engineer

Interview with Engr. Jonathan Hensel

Interview with Engr. Jonathan Hensel

Interview with Engr. Jonathan Hensel - Prototype Design and Reverse Engineer at Epec Engineered Technologies

Can you give us a little background about yourself?

I come from a family of tinkerers, artists and inventors. None particularly successful at any of the above, but if pride of workmanship counts, we would be considered prosperous. I can’t remember a time as a kid where I wasn’t disassembling something, attempting to reassemble it, failing miserably often, and causing a few minor workshop fires. My grandfather, a shoe cobbler, brought the clan over on a ship from Germany in 1927, and lived with all of us until the ripe old age of 96. He would spend his free time “gruesheling” as my grandmother called it, in his workshop, making film projectors and cameras from scrap, riding lawnmowers from spare parts, fixing the old Model A. He was a savant and I’d love to sit and help him for hours.

I never found a true translation for the word or for most of the quasi I German/French gibberish that he spoke, but I do still grueshel to this day.

How did you get into Engineering?

I am fairly certain that I have never even considered anything else. Like any young whippersnapper gearhead, I couldn’t wait for shop, math & drafting classes – then modifying my cars and motorcycles in my free time. During my senior year of high school in 1987, I was allowed to take the first AutoCad class that was offered at the local city college in the evenings. If it wasn’t already fate by then, it surely locked engineering and design into my sights when computers showed up on the scene.

Out of many fields of engineering expertise to choose from, why Prototype Design and Reverse Engineering?

I’d say the challenge and the creativity. The creative aspect of starting with a blank screen and a couple of concepts bouncing around in your head to then seeing the evolution of your ideas come to fruition. I find it to be completely fulfilling. And trying to figure out what was in the head of the engineer of an original design, what was the purpose behind why he did this or did that, how we can improve on the product or the process. I’d say there’s no bigger challenge than trying to mind-read an engineer!

What do you like best about being a Prototype Design and Reverse Engineer?

I’ve had the opportunity to be involved in a diverse array of projects, complex scientific instruments, high bandwidth servo systems, industrial machinery, electro-opto-mechanical devices. I myself have had to invest in materials science and the multitude of fabrication techniques available. If you don’t know how your parts get made, you’ll never be successful at designing them in the first place. I also enjoy learning how to use the machines that make the parts and the techniques that the journeymen use to work their magic to get to the final product. It has always been important to me.

You are now a Prototype Design and Reverse Engineer at Epec Engineered Technologies, kindly tell us what you do (your line of work) and how do you find your current responsibilities?

At Epec Engineered Technologies, I am focused on expanding our custom design, development and manufacturing presence in the industry. Additionally I am preparing our new manufacturing facilities to meet the demands of our Cable Assembly / Wiring Harness and Engineered Fan / Motor technologies. I enjoy every aspect of being a “man wearing many hats”.

Where do you see your company (Epec) heading?

We are broadening our range of expertise into new growth markets and cutting edge technologies. Recently we’ve gained some unique manufacturing capabilities that have put us at the forefront of custom-designed electromechanical devices. There’s a culture of commitment in putting the highest quality product on the table every time, and a dynamic ability to innovate that seems to emanate from the top down through the ranks. With the talent and the philosophy that we have here at Epec, I see no boundaries for our growth potential.

Being on the field of Prototype Design and Reverse Engineer, which prototype designs were your personal favorite and why?

The original MFP-3D Atomic Force Microscope was my favorite and then its gold-standard successor, the Cypher Modular Atomic Force Microscope.

Can you tell us what an Atomic Force Microscope is?

An AFM is a tactile 3 axis scanner capable of taking a digital 3D topographical image on the nanoscale level, orders of magnitude more powerful than any optical microscope.

A simplified explanation would be to think of a phonograph needle as it bumps up and down along the inscribed grooves of a record, then converting the vertical movement of the stylus to analog waveforms based on current generated in the surrounding coil. Combine that with the mechanics of an old raster printer, as it would sweep across the paper from edge to edge printing a line, then step down to the next line and sweep across. Basically an X motion, a Y motion combined with a Z motion.

An AFM is used to perform Scanning Probe Microscopy by taking an ultra-small probe tip that is “grown” onto the end of a silicon nitride cantilever, similar to a miniature diving board and whose resonant frequency is calibrated and recorded. A laser is reflected off the surface of this cantilever on the opposite side of the probe tip. The reflected spot is directed upon an optical position detector, usually a sectioned position-sensitive photodiode which can measure the movement of the sweep of the laser beam as the cantilever is deflected or twisted. We now have a digital, highly accurate version of a phonograph stylus.
This unit is usually called the “Head”, we mount to a “Z” axis stage which positions the cantilever upon or just above the specimen surface and maintains a safe distance from any undulations or impediments. The specimen surface is mounted on an “X-Y” scanner which rasters beneath the “Z” stage. All 3 axes are closed loop so we know where that tip is in space at any time relative to any features on the specimen surface. The resultant output is a series of coordinates than can be interpolated by software to create a three dimensional image. Fast scanners can do this quickly and repeatedly creating real-time video with live biological samples or chemical reactions in-situ at the atomic level.

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Additionally, the probe tips can be excited and “peck” at the surface during the scan, called “tapping mode” extending the life of the probe. They can be excited just above the surface and the modulation of the return wave then measured for use in non-destructive measurements. They can be coated with different functional materials or charged to grab on to the specimen, like a helix of DNA for example. An array of cantilevers on a chip called a “sniffer” can be coated with different materials and measured concurrently to analyze certain compounds or reactions. An “indenter” can be substituted for the lever, measuring the force required to make a certain sized notch in a certain material.

The need for a modular system to incorporate the variety of new complex measurements, faster scan times, and cleaner feedback led to the design of a new breed of high resolution equipment that I was heavily involved in for several years: http://patents.justia.com/inventor/jonathan-hensel

What are you currently working on (If it’s confidential, kindly only give us an overview)?

I am troubleshooting several Avionics Interface Panels for a new customer as well as working on a remote control device for a customer in the medical industry.

What is the trickiest bug you have fixed?

I had the task to design an ultra-thin X-Y flexure nano-positioner capable of scanning biological specimens in either petri dishes or on microscope slides which are then mounted on a custom stage on top of a standard inverted optical microscope. Any out-of-flatness in the Z-plane on an X-Y scanner causes distortion and errors in the readings and since we had to accommodate the short focal distance of a standard objective, we had to design our stage very thin, about 7/16” thick. Traditionally we would push a stage back and forth with a pair of trapezoidally mounted piezos, but this would create buckling and an out-of-flat condition in the Z-plane of our sub-optimally weak flexure stage. The fix I came up with was to “pull” the stage with a side mounted lever-arm and a “strap” that was created by machining both sides of the EDM’ed bridge that spanned from the end of the lever-arm to the stage creating in essence a pull strap that would impart no undue Z forces. This is the stage that is still sold as a part of the MFP-3D AFM today and 12 years after serial number 0001 went out the door; we maintain a zero failure rate.

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What is on your bookshelf?

It took a while, but I am happy to say I’ve successfully made the transition to the digital age so most research material can now be harnessed through the multitude of LED screens at my disposal. For nostalgia’s sake I still hold on to my old Machinery’s Handbook and my little red book of Engineering Formulas.

Do you have any experiential stories you’d like to share? (Blowing things up, getting shocked, etc.?)

Nothing too far out, by hook or by crook I made it through my childhood with all of my appendages intact. My friends and I really got into flying R/C aircraft when we were younger and started last-man-standing midair wars. Midair collisions are actually more difficult than one might think so to cure the “boredom” we’d attach explosive caps to the aircraft so when we finally did make contact it was quite a sight. We later added bottle rocket artillery troops, pellet gunners, and roman candelier ground forces laying a constant barrage at the dogfight.

Inevitably we’d start shooting at the pilots themselves (ourselves). I think one of my pellets is still embedded in Eddie Mendez’s kneecap these many years later. Unfortunately…… or fortunately, our battlefield happened to lie directly in the approach path to the local airport so the local constabulary shut us down before things got out of hand.

What do you do when you’re not working on prototype designing?

I enjoy traveling. I’ve had the fortune of taking 3 continental road trips in the last ten years. I’ve driven to the Arctic Ocean and throughout Alaska via the Al-Can highway and took the inside passage back on a ferry stopping in Juneau, Sitka and Ketchikan. Then this last trip lasting a year, took me from southern California 25,000 miles of zig-zagging north and south in an easterly direction ending up in Maine & Nova Scotia. I darted south to Florida before this past winter hit and have made my home here in the Tampa area.

What direction do you see yourself heading in the next few years?

I enjoy diversifying my expertise. Since I am an M.E. by definition my electronics skills have always played second fiddle to my mechanical capabilities. Now I have joined a thriving electronics-driven group at Epec, hoping to merge my strengths with theirs enhancing the company skill set as well as my own.

Is there anything you’d like to say to young people to encourage them to pursue engineering?

If you’re genetically engineered for it, there is nothing more rewarding. I couldn’t imagine any other profession. And don’t pigeonhole yourself into one discipline too early, try a few and decide based on that experience. I originally wanted to go into civil engineering but once I started playing around with micro-mechanisms I knew where I wanted to focus.

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