Navbar2

Homepage

Industry Experience on demand. Connect with experience engineers to enhance your technical skills tailored for internship and entry level job seekers

Low Intertia | Empowering Engineers

FooterSection

Screen

react-awesome-reveal

plasmic-nav

react-scroll-parallax-global

plasmic-query

uuid

plasmic-basic-components

Low Inertia

react-aria

plasmic-cms

plasmic-rich-components

antd5 hostless

react-parallax-tilt

<h2><strong id="docs-internal-guid-43359b28-7fff-598d-b998-88dd398c2cfd">Instructions</strong></h2>
<p dir="ltr">These Questions require written responses with sketches, and some may need CAD models (not in this set). In actual interview, you&rsquo;ll typically have 1-2 hours. Don&rsquo;t be discouraged if it&rsquo;s tough. We can help you learn! If it&rsquo;s not, you&rsquo;re well-prepared!</p>
<p dir="ltr">Assume designs are for mass production and cost, assembly, and reliability needs to be considered. Sketches alone may not show subtle decisions&mdash;explain assumptions and reasoning for context. Try to show your work; sketches reveal your problem-solving process. This will be a great practice!</p>
<p>&nbsp;</p>
<h2><strong id="docs-internal-guid-cc2ff6b8-7fff-f428-eb62-8e9dd1ea05b3">Question 1</strong></h2>
<p dir="ltr">There is a water-filled chamber with two hot plates directly beneath it, each equipped with its own cartridge heater and thermistor for independent temperature control. In order for certain reactions to happen, the chamber needs to have an area between 31&plusmn;1C and 88&plusmn;1C.</p>
<p dir="ltr">Assumption: Uniform and correct temperature in the hot plates. Only consider steady state. Don&rsquo;t worry about the initial heating. The chamber is made out of acrylic.</p>
<p><img style="width: 500px; max-width: 100%; height: auto; display: block; margin-left: auto; margin-right: auto;" src="https://img.plasmic.app/img-optimizer/v1/img?src=4c1a9e294c5645f0a424fe11471d829d.png&amp;f=webp&amp;q=75" width="336" height="150"></p>
<ol>
<li>Draw a simple sketch of what you would expect the temperature gradient to look like at steady state</li>
<li>Draw a simple sketch of what you would expect the zone of 32&plusmn;1C and 88&plusmn;1C would be located.</li>
<li>What would happen if the chamber was made out of the following materials instead?
<ol>
<li>Glass</li>
<li>Aluminum</li>
</ol>
</li>
<li>In real life without making any assumptions, what can go wrong in this design? How would you mitigate it?</li>
<li>How would you optimize this design to maximize volume of 32&plusmn;1C and 88&plusmn;1C zones.</li>
</ol>
<p>&nbsp;</p>
<h2><strong id="docs-internal-guid-cc2ff6b8-7fff-f428-eb62-8e9dd1ea05b3">Question 2</strong></h2>
<ol>
<li>Assess the design&rsquo;s strengths and weaknesses, highlighting any critical flaws or benefits.</li>
<li>Suggest potential improvements to enhance the system.</li>
<li>Identify possible second-order effects that may need further analysis or testing.</li>
</ol>
<p><img style="width: 500px; max-width: 100%; height: auto; display: block; margin-left: auto; margin-right: auto;" src="https://img.plasmic.app/img-optimizer/v1/img?src=27be0ac287ce5c4ea59a35dbbd2937b8.png&amp;f=webp&amp;q=75" width="376" height="169"></p>
<p>&nbsp;</p>
<h2><strong id="docs-internal-guid-cc2ff6b8-7fff-f428-eb62-8e9dd1ea05b3">Question 3</strong></h2>
<p dir="ltr">A future prototype needs a subsystem to deliver even clamping pressure to an assembled consumable with this geometry. There is a 2mm zone between the raised and lower surfaces where clamping pressure isn&rsquo;t required. The thickness of the parts are irrelevant. Let&rsquo;s assume that they have stainless steel backing.</p>
<p><img style="width: 500px; max-width: 100%; height: auto; display: block; margin-left: auto; margin-right: auto;" src="https://img.plasmic.app/img-optimizer/v1/img?src=bd8e060816a5d9a7b692227d11c66e76.png&amp;f=webp&amp;q=75" width="419" height="105"></p>
<p dir="ltr">The requirements are as follows:</p>
<ol>
<li dir="ltr" role="presentation">The system needs to apply 15 PSI evenly across the entire surface of 1 sq in</li>
<li dir="ltr" role="presentation">The force distribution across the area needs to be less than 2 lbf.</li>
<li dir="ltr" role="presentation">The system goes through 1 million cycles of heating and cooling between 120 F to 35F.</li>
<li dir="ltr" role="presentation">This clamping system needs to be completely automated.</li>
</ol>
<p dir="ltr">Design a high-level system design that would achieve this. Also, How would you verify that the requirements are being met?</p>
<p>&nbsp;</p>
<h2><strong id="docs-internal-guid-cc2ff6b8-7fff-f428-eb62-8e9dd1ea05b3">Question 4</strong></h2>
<p dir="ltr">There is an optics system with a camera and LED illumination source mounted on a linear actuator. The camera subsequently takes images of samples at 4 stations every 30 seconds.</p>
<p><img style="width: 500px; max-width: 100%; height: auto; display: block; margin-left: auto; margin-right: auto;" src="https://img.plasmic.app/img-optimizer/v1/img?src=d06be59e9cf54ae843fddc27f5255a0b.png&amp;f=webp&amp;q=75" width="385" height="149"></p>
<ol>
<li>Once all components were installed, you began gathering images. However, the image captured at station 1 is blurry. Identify all potential reasons that could lead to this issue.</li>
<li>Drawing from your responses to question 1, how would you enhance the design or reduce the associated risks?</li>
</ol>

dlxmedia-hu-pakTZIspHO0-unsplash.jpg

Technical Assessment # 1

<div>A catheter was returned as defective. The description to the failure says a malfunctioning camera at its tip (bad image). The camera is potted with UV-cure adhesive within the cavity at the tip and connected using a micro-coaxial cable which is snaked through the luemn (a hollow channel or passageway within the catheter shaft) the shaft of the cateter.&nbsp;</div>
<div>&nbsp;</div>
<div>Identify potential failure modes and explain the steps you would take to investigate and determine the root cause.</div>

A catheter was returned as defective...

<p dir="ltr" data-pm-slice="1 1 []">Determine the temperature at the cartridge heater embedded in a perfectly conductive material on the inner surface of a 0.1 m thick aluminum wall (thermal conductivity k = 200 W/m&middot;K, area A = 1 m^2). The cartridge heater provides a steady-state heat flux of 20000 W/m^2 through the wall via conduction. The outer surface of the wall is in perfect thermal contact with a consumable cartridge, which is maintained at a constant temperature of 30&deg;C to facilitate a heating process. Ignore radiation effects. What is the temperature at the cartridge heater (inner surface of the wall)?</p>

The heat conduction through the aluminum heater block

<div>When attempting to establish a serial connection to the motion controller with the provided script, a <code>ModuleNotFoundError</code> occurred. What is the <strong>most common</strong> the reason for this error?</div>
<div>&nbsp;</div>
<p><img style="max-width: 100%;" src="https://img.plasmic.app/img-optimizer/v1/img?src=a00f1c6bc9177c2c79a66be4689414a0.png&amp;f=webp&amp;q=75" alt="Motion controller connection diagram"></p>

Using Python, make serial connection to motion controller 

<div class="markdown-heading" dir="auto" style="text-align: left;"><a id="user-content-free-to-engineer-portfolio-template" class="anchor" href="https://github.com/leea12/free-to-engineer-portfolio-template#free-to-engineer-portfolio-template" aria-label="Permalink: Free to Engineer Portfolio Template"></a></div>
<p dir="auto" style="text-align: left;">With the growing emphasis on practical skills, more companies are looking at portfolios alongside traditional resumes when evaluating engineers. I would highly recommend putting one together. A well-crafted portfolio can showcase your projects, technical abilities, and problem-solving approach in ways that resumes alone cannot. This is a free portfolio template. You can host your site for free in Github in&nbsp;<strong>15 minutes</strong>! Check out the&nbsp;<strong>demo&nbsp;<a href="https://leea12.github.io/" rel="nofollow">here</a></strong>. In order to publish the projects, you need to know how to write in markdown format. I have the basic instructions below so feel free to give it a try.</p>
<div class="markdown-heading" dir="auto"><a id="user-content-adding-projects" class="anchor" href="https://github.com/leea12/free-to-engineer-portfolio-template#adding-projects" aria-label="Permalink: Adding projects"></a></div>
<p style="text-align: left;">For detailed instruction, check out the&nbsp;<a href="https://github.com/leea12/free-to-engineer-portfolio-template">page on github</a></p>
<p style="text-align: left;"><img src="https://img.plasmic.app/img-optimizer/v1/img?src=6f0789a1f357164c273d1caa95ccf890.png&amp;f=webp&amp;q=75" width="362" height="223"></p>

Screenshot 2025-02-22 at 1.06.11 PM.png

Free portfolio website template you can use to host for free on Github. 

Free Portfolio Template

<p>First, I wanted to explain why I think exercises like this are valuable. The problem sets I&rsquo;ll share simulate a range of mechanical design challenges that are highly relevant to product development at companies designing instruments with optics, thermal, and mechatronic components. Many innovative companies&mdash;especially startups&mdash;assign these kinds of tasks to assess your critical thinking and your ability to apply core physics and engineering principles to solve problems or refine designs. In the following problem sets, I&rsquo;ll aim to cover diverse topics and technologies.&nbsp; You will be able to recognize your strengths and pinpoint areas for growth.</p>
<h2>&nbsp;</h2>
<p>&nbsp;</p>
<h2>Usual Format</h2>
<p>These challenges typically come in two forms: real-time or take-home.</p>
<h3>&nbsp;</h3>
<h3>Real-Time:</h3>
<p>Since you&rsquo;ll tackle the questions live, CAD modeling won&rsquo;t be involved. Expect a mix of problems testing engineering principles, your understanding of design constraints, and simple conceptual design skills.</p>
<h3>Take-Home:</h3>
<p>You&rsquo;ll usually have a set time limit&mdash;often around 2 hours. It may include some CAD design tasks.&nbsp;Years ago, a major 3D printing company had me complete a challenge in the third interview round, followed by a discussion with their head of engineering. It was a fair and insightful process.</p>
<p style="padding-left: 40px;"><strong>Warning:</strong> I&rsquo;ve seen small startups assign tasks that took 8&ndash;10 hours, which I consider excessive and a warning sign. In some cases, it felt like they were using interviews to brainstorm solutions to their own problems&mdash;something to be cautious about.</p>
<div class="__wab_flex-container &rho;fc">&nbsp;</div>
<h2>&nbsp;</h2>
<h2>Structure</h2>
<ol>
<li>Theoretical questions in topics like (statics / dynamics / thermal / fluids)</li>
<li>Simple concept design sketch</li>
<li>Evaluate the given design for manufacturability / rough cost estimate / material selection. How would you improve the design? How would the volume of production change the way you approach the design?</li>
<li>Simple conceptural design to see the ability to come up with most simple and cost effective design</li>
<li>More complicated CAD design that will challenge the understanding of enginering constraints and recent technology developments. could cover topics like vibration, required assembly precision, optics performance, thermal performance, power transmission</li>
</ol>
<h2>&nbsp;</h2>
<h2>&nbsp;</h2>
<h2>&nbsp;</h2>
<h2>What&rsquo;s the Point of All This?</h2>
<h3><br><strong>I think companies are increasingly using this approach for these key reasons:</strong></h3>
<p><strong>Resumes Aren&rsquo;t Enough</strong>: It&rsquo;s tough to gauge someone&rsquo;s real abilities from a resume alone. I&rsquo;ve spoken with candidates who had stellar resumes, only to learn the work wasn&rsquo;t theirs ask I asked detailed questions. Hiring is a big deal&mdash;especially for small teams&mdash;since training and onboarding can shake up workflows.</p>
<p><strong>This Mirrors Real Work</strong>: These tasks replicate actual job scenarios. You&rsquo;re welcome (and encouraged) to ask questions, revealing how well you&rsquo;d mesh with a team. Also, often, many companies look for "specific skills" that were identified as a gap in the team. So, often times, the questions would geared towards that specific skills.</p>
<p><strong>Communication Is Key</strong>: Even for engineers, clear communication is non-negotiable. We rely on teamwork and trust in each other&rsquo;s work. Visual communication, especially, is vital&mdash;your sketches, explanations, and notes don&rsquo;t need to be artistic, but they must be crystal clear to anyone reading them.</p>
<h2>&nbsp;</h2>
<h2><br>Conclusion</h2>
<p>I&rsquo;m convinced this interview style will grow more common, particularly among smaller startups. I encourage you to invest time and effort in sharpening these skills&mdash;it&rsquo;s an investment that will pay off in the long run.</p>

Empowering Current and prospect engineers

Start Exploring

Useful Resources

Industry Experience

Empowering Current and prospect engineers

Start Exploring

Useful Resources

Industry Experience

Let's Unleash your Potential