Engineering Intern

Job Title: Engineering Intern – Materials & Resin Development

Company: SprintRay Inc.

Location: Huntington Beach, CA

Duration: 3 Month Internship

Compensation: $22-$23/hr

About the Role

SprintRay’s Biomaterial Innovation Lab is seeking an Engineering Intern to support the development of next-generation dental 3D printing resins for DLP and LCD printing platforms. This hands-on, on-site lab role involves contributing to resin formulation, print process evaluation, post-processing studies, and material characterization. You will collaborate with a cross-functional team to generate data, troubleshoot performance issues, and accelerate iteration on new resin systems.

Key Responsibilities

• Assist in photopolymer resin formulation (mixing, batching, additive screening, pigmentation, and process controls).
• Support experimental planning and design-of-experiments (DOE) to evaluate formulation and process variables.
• Run DLP and LCD 3D printing trials to assess printability, cure response, feature fidelity, accuracy, and surface quality.
• Evaluate process windows (exposure settings, layer thickness, build orientation, supports) and document outcomes.
• Support post-processing optimization (cleaning/washing, UV curing, thermal treatments) and quantify impacts on properties.
• Perform materials testing and characterization on resins and printed samples, including:
• Viscosity / rheology measurements
• Cure behavior / degree of cure
• Mechanical testing (tensile/flexural/compression, hardness)
• Dimensional accuracy, shrinkage, and stability
• Visual/optical properties (color, translucency)
• Analyze and summarize data; maintain clear lab documentation (notebooks, protocols, reports, and traceable datasets).
• Collaborate with engineers/scientists to troubleshoot issues and propose improvements.
• Follow all lab safety procedures and quality practices applicable to medical device development.

Requirements & Tech Stack

• Minimum Bachelor’s degree (completed or in progress) in Biomedical, Chemical, Mechanical Engineering, Materials Science, Chemistry, or a closely related field.
• Ability to work on-site in Huntington Beach, CA for the full internship term (3–6 months).
• Hands-on lab experience (academic or industry) in materials, polymers, chemistry, formulation, or testing.
• Comfort working with data and documentation (Excel/Google Sheets; basic plotting/analysis).
• Strong communication skills and ability to work effectively in a team environment.

Preferred Qualifications

• Experience with photopolymers, resin chemistry, polymers, or composites.
• Familiarity with DLP and/or LCD printing workflows and parameter optimization (exposure, layer thickness, supports).
• Experience with characterization tools (e.g., viscometer/rheometer, FTIR, DSC/DMA, mechanical test frames).
• Interest in digital dentistry, dental materials, or medical device R&D.
• Exposure to regulated development environments (ISO 13485, GMP) is a plus.

What You’ll Gain

• Hands-on experience developing and validating dental 3D printing resin materials for DLP/LCD platforms.
• Mentorship from a multidisciplinary team across materials, process, and device development.
• Opportunity to contribute to new products and workflows in a fast-moving digital dentistry environment.