Senior Mechanical Engineer

Wilmington, MA
About Us:

Headquartered in the Boston, Massachusetts area, Liberty Defense is a public and emerging security and detection technology company focused on designing, building, and delivering, next-generation security screening sensors that form a layered-security solution for the world-wide marketplace.

We are in the process of launching our first product in beta trials around the US, addressing a wide variety of markets.  We recently received a government funding award that validates our technology and will serve to accelerate our time-to-market.  With the additional backing from our shareholders, we are now poised to expand on our cutting-edge product development portfolio.  With an experienced security industry leadership team and advisor network already in place, we are passionate about our mission.  If you’re excited about the potential of joining a security technology company that is ready to alter the industry landscape, then read on . . .


The Role and Responsibility:

We’re looking for an Sr. Mechanical Engineer to join our rapidly expanding team to support our design activity and the transition to production of our advanced radar and millimeter-wave based people screening platforms for the aviation and commercial markets.  The successful candidate will be part of the Engineering team and work in conjunction with Operations and Program Management to support the lifecycle product development of our Personnel Threat Detection Security Products, including production vendor support, regulatory testing, and support for customers who face issues with technical equipment.  The associate mechanical engineer will also help design and conceptualize mechanical assets, construct, and install mechanical parts, and resolve mechanical problems in the different machines they work with.


Responsibilities include:

  • Perform lifecycle product development activities (design, develop, test prototypes, mfg. and implement)
  • Design mechanical systems and sub-systems, including and parts / components that meet the product requirements.
  • Can work on their own and closely with other Engineering Staff on design issues, as well as work with the Operations Team to identify and support Production vendor sourcing for components.
  • Produce outline designs.
  • Conduct experiments methodically, analyze data, and interpret results.
  • Estimate material costs for projects and analyze quotes and bids to assist Engineering and Operations in vendor selection
  • Prepare product design and system documentation
  • Engage in learning and continuously improve fabrication and assembly methods
  • Ability to travel up to 10% time, or as required



  • Bachelor’s degree in an engineering discipline required.
  • 5 to 10 years of related experience highly preferred.
  • Mechanical and electrical aptitude
  • Experience with a variety of plastic materials and fabrication methods
  • Problem-solving abilities
  • Proficient with Mechanical Design applications such as SolidWorks and/or OnShape
  • Ability to diagnose problems with the right equipment
  • Ability to work independently and be effective in a fast-paced environment. Strong team player and willing to work collaboratively across the organization.



  • Familiar with design for manufacturing (DFM) practices to minimize parts and packaging costs in production.
  • Familiar with FCC EMI/EMC regulatory rules and methods of electronic package shielding designs.
  • Exposure to designing components for Airport Security, Utilities, telecom, or electronics fields
  • Experience with RF systems


We Offer:

  • Competitive Salary and Bonus.
  • Comprehensive Benefit Plan, health, dental, and vision coverage, retire plan and STD/LTD disability and life insurance.
  • Flexible working arrangements


We are an Equal Opportunity Employer and are committed to a workplace free of discrimination and harassment. We recruit, hire, and promote associates without regard to race, color, sex, religion, sexual orientation, gender identity, national origin, age, veteran status, or any other status protected by federal, state or local laws.