1. What experience do you have working with suppliers or fabricators to source parts or assemblies? How do you evaluate cost, quality, and lead time tradeoffs?
As a designer, I regularly work with suppliers and fabricators to source parts and assemblies. My role involves releasing detailed 2D and 3D drawings, and for assemblies I provide exploded views and a complete BOM to ensure clarity. Typically, I obtain quotes from two to three suppliers, but I also rely on trusted partners with whom I’ve built strong relationships over many years. Having reliable suppliers is critical to project success. Earlier in my career, I encountered issues when selecting a low‑cost supplier without fully validating their processes. This led to inconsistent paint quality and significant rework. From that experience, I learned the importance of balancing cost with quality and lead time. Now, I always review suppliers’ processes step by step, align on a quality control plan, and evaluate tradeoffs in detail. For example, in zinc plating, there are multiple process options, each with different costs and levels of rust resistance. By breaking down these differences, I can make informed decisions that balance performance, reliability, and budget. Ultimately, my approach is to treat supplier collaboration as a partnership—ensuring transparency, process control, and attention to detail so that the final product meets both technical and business requirements
2. Have you designed waterproof or sealed enclosures before? Please briefly describe.
Yes, I’ve designed a lot water proof devices. My current projects include smart lock and camera, all require good water sealing. The tests are from IP64 to IP 68, and UL rain test. Different tests require different level of design. Design-wise, the rule of thumb is to make clean and simple splitting line from the enclosure, while maintain all other requirements. Once this is done, we just need to consider the ideal sealing method. Consideration include what kinds of sealing agent, cost to achieve it ,rework ability and impact from temperature over time, etc
3. Can you deliver STEP + STL files that are ready for 3D printing and CNC?
Yes, that’s for sure. I can also provide good CNC /3D print sample with competitive price
4. Describe a project where you reduced manufacturing cost on an existing mechanical design. What changes did you make, and what was the impact?
In several product improvement projects, I identified opportunities to reduce manufacturing costs by rethinking the design approach. For example, I discovered that certain geometries could be achieved using sheet metal instead of CNC machining, with tolerances still within acceptable limits. By replacing CNC parts with sheet metal components manufactured through laser cutting and bending, production costs were significantly lowered. Additionally, I consolidated multiple small parts into larger integrated components, which not only reduced the total part count but also simplified fabrication. In one wristband project, the original enclosure design was overly complex in how it was split. I proposed a cleaner, more efficient method of splitting the enclosure, which made the parts easier to manufacture and improved assembly reliability. This redesign also enhanced the product’s water sealing performance, delivering both cost savings and functional improvements.
5. Tell us about a handheld or compact device you worked on that included electronics (PCBs, sensors, displays, wireless, or batteries). What mechanical constraints were most challenging?
During my time at ASUS, I worked on laptop designs that presented significant mechanical challenges due to their compact form factor. The two most critical issues were EMI compliance and thermal management. With multiple high‑speed signals around the display and the main board, passing EMI tests on the first attempt was rare. This required close collaboration with the RF team and several rounds of testing to eliminate noise, especially since the enclosure was made of plastic, which offered limited shielding. Thermal constraints were equally demanding. The requirement for a slim, lightweight device left very little space for conventional cooling solutions. To address this, I worked closely with the thermal engineering team and suppliers to explore innovative heat dissipation methods and optimize component placement. Ultimately, we achieved a balance between cost and performance, ensuring the device met both regulatory and functional requirements while maintaining the compact design.
6. Have you taken a prototype from early builds into production or pre-production? What issues typically surfaced, and how did you resolve them?
Yes. During my 10 years at a design firm, I gained extensive experience transitioning prototypes into pre‑production and full production. One of the most common challenges was that early prototypes were not optimized for mass manufacturing. For example, designs intended for 3D printing often had to be re‑engineered for injection molding, which requires different draft angles, wall thicknesses, and parting line considerations. Similarly, CNC‑machined metal parts were frequently converted to processes such as die casting, sheet metal fabrication, or metal injection molding (MIM) to achieve cost efficiency at scale. Resolving these issues required careful redesign of mechanical components to align with the chosen manufacturing process, while maintaining functionality and aesthetics. By collaborating closely with suppliers and manufacturing engineers, I ensured that the revised designs met production requirements, reduced costs, and improved manufacturability without compromising product quality.
7. Describe one consumer hardware product you helped take from concept to mass production. What engineering decisions were you personally responsible for, and what trade-offs did you make?
I’,d like to share a windshield repair machine I worked before, the device can emit a special wavelength of light to cure a special UV glue that spread on the cracks of windshield. It has a suction mechanism to be fix on the windshield and a defined light illumination area . The light intensity has to be uniform across the target area. The challenges are 1.The lever triggered suction mechanism has to be reliable and small 2. The lens design has to meet the illumination uniformity 3. the enclosure has to be water-tight 4. it has to pass 1.5meter free drop test One of the engineer decision I made is the enclosure material. Since it is used in environment contain many chemical solvent , exposed UV light, and rug factory. I chosen Nylon with fiberglass infilled that meet all the requirements and by adding fiber glass, the injection part can achieve acceptable tolerance. One trade-offs I remember is a metal bracket that serves 2 purposes, one is heat dissipation and another is to provide support during a impact. The material with better heat dissipation rate is softer, while the stronger one is not that good in heat. And after discuss with the client and conclude that the impact of 2 degree temperature increment is much less significant to giving out a weak product impression to user. As a result ,I opted for the stronger metal in that design.
8. Tell us about a situation where electrical, thermal, and mechanical constraints conflicted. How did you decide what to prioritise, and what was the outcome?
While designing a camera, the antenna required a non‑metal enclosure, but the PCB generated significant heat in a very limited space.
Decision: Functionality was prioritized, as the new features were the product’s key selling points. I adopted a hybrid material enclosure that preserved antenna performance while keeping temperatures within acceptable limits.
Outcome: The solution increased assembly complexity and cost, but it successfully balanced RF performance with thermal management, enabling the product launch.
9. Have you supported products through safety or EMC certification (IEC / UL / CE / FCC)? What was your role, and what engineering mistake or surprise did you learn from?
I supported products through IEC, UL, CE, and FCC certifications while working on laptops (ASUS),smart locks, and cameras. My role included:
Preparing CAD files for solutions
Building and supplying test units
Collaborating with compliance, RF, and EE engineers to evaluate feasibility
Lesson learned: Certification tests are unforgiving. In one case, I mistakenly used a grade 2 screw instead of grade 8 high‑strength during testing, leading to failure. It reinforced the importance of meticulous preparation and attention to detail.
10. What product that has been launched to market are you most proud of? Please describe your role, the key challenges, and why this product stands out to you.
The project I am most proud of is a smart lock system developed for a UK client. I collaborated closely with their mechanical team (two senior engineers and one junior engineer) and took responsibility for one of the three lock models.
Key challenges:
Meeting ANSI Grade 1 and UL 294 standards
Passing multiple compliance and durability tests
Achieving extremely high strength and long‑term reliability
My role: I coordinated design reviews, prepared solutions, and maintained close communication with the UK team through 2–3 weekly meetings.
Outcome: After more than one year of development, the product successfully launched. The project deepened my expertise in materials and manufacturing processes, and it stands out as a milestone in balancing stringent compliance with innovative design.
M-Star Product Design 