About the role

We are developing a miniaturized focused ultrasound (FUS) medical device and are hiring a Lead Ultrasound Engineer to own the acoustic heart of it. This is a hands-on technical leadership role: you will design and build custom piezoelectric transducers, manage the curation of the device as it evolves from prototype to product, and drive the engineering trade-offs that make precise focused ultrasound possible in a genuinely small form factor.

The role spans the full arc of device development — piezo materials and acoustic stack design, focusing and targeting, fabrication and iteration, rigorous testing and characterization, and deep R&D into what the next architecture should be. You will work shoulder to shoulder with electrical, mechanical, firmware, and clinical teams to integrate the acoustic front end into a complete system, and you will be accountable for its performance, safety, and manufacturability.

What you'll do

• Design and build custom piezoelectric transducers for focused ultrasound — material selection (PZT, single crystal, composites), element geometry and array design, matching and backing layers, and acoustic stack optimization for efficient, precise energy delivery.
• Manage the curation of the device: own the evolving device architecture, component and material selection, BOM, and supplier relationships as the design matures from bench prototype toward a manufacturable medical device.
• Lead the miniaturization effort — drive size, power, and performance trade-offs across the transducer, drive electronics, interconnects, packaging, and enclosure to reach a compact, patient-friendly form factor without compromising focal precision or safety.
• Build and run the testing program: acoustic characterization (hydrophone field mapping, focal pressure and beam profiling, electrical impedance), tissue-mimicking phantom testing, thermal and cavitation safety verification, and design V&V aligned with medical device standards.
• Conduct hands-on R&D — prototype novel transducer and focusing architectures, model acoustic propagation, evaluate emerging materials and steering approaches, and turn findings into clear roadmap decisions.
• Partner closely with electrical, mechanical, firmware, and clinical teams to integrate the transducer with drive and control electronics and the full device system.
• Set technical direction for ultrasound engineering — run design reviews, document decisions, mentor engineers, and raise the bar on rigor across the hardware team.

What we're looking for

• 4+ years of engineering experience in therapeutic ultrasound, with significant hands-on transducer development that has shipped in real products or clinical systems; focused ultrasound experience strongly preferred.
• Deep expertise in piezoelectric transducer design and fabrication — piezo materials, acoustic stack modeling (KLM, FEA tools such as COMSOL or OnScale/PZFlex), focusing and lensing, matching, and backing design.
• Strong command of acoustic test and characterization methods: hydrophone field mapping, beam profiling, impedance analysis, and acoustic output and exposure measurement (ISPTA, MI/TI, IEC 62555/61161).
• Understanding of therapeutic ultrasound physics — tissue attenuation and aberration, standing waves, and thermal and cavitation safety margins.
• Experience developing devices under medical device design controls (ISO 13485) and familiarity with relevant standards such as IEC 60601 and FDA guidance for ultrasound devices.
• A track record of miniaturizing complex electromechanical or medical devices — dense interconnects, flex circuits, packaging, and thermal constraints in small form factors.
• Proven technical leadership: driving architecture decisions, mentoring engineers, and being accountable for outcomes across a multidisciplinary team.
• Pragmatic judgment about when to build, when to buy, and when to keep it simple.

Nice to have

• Prior work on focused ultrasound therapy systems (LIFU) or phased-array beam steering.
• Experience with MEMS-based ultrasound (pMUT/cMUT) or other emerging transducer technologies.
• Familiarity with acoustic simulation tools (k-Wave or similar) and image-guided or sensor-guided targeting.
• Hands-on work with wearable or compact medical devices and their unique power, ergonomic, and regulatory constraints.
• Cleanroom fabrication experience and design-for-manufacturing work with contract manufacturers.

Why We Exist

Mental health is an epidemic that's getting worse day by day. Depression, anxiety, ADHD, suicide, and PTSD are at an all-time high. This needs to change. We humans were not made for this sort of life. We were never designed for the sedentary, indoor, socially isolated, fast-food-laden, sleep-deprived, frenzied pace of modern life. We are being robbed by the same tech that was meant to add value to our lives. It's time for a change.

Our team at Mellow Labs is building the future of mental health by bridging the gaps between science and mental health. Our aim as an organization is to create systemic impact, especially in underrepresented populations. We are currently building for women's brain health, as it's an area with poor clinical and scientific validation.

1993 — the first-ever clinical trials were conducted on women. 1996 — the first-ever brain scans on women. Only 1% of all brain scans represent a woman's brain, and our team wants to change that by bringing neurotechnology to women to improve their mental health.

The Team You’ll Join

You’ll work alongside a world-class mental health team — neuroscientists, clinicians, researchers, and engineers who have dedicated their careers to understanding the brain and closing the gender gap in brain health. This means your day-to-day includes conversations most developers never get to have: reviewing features with scientists who study the very signals your app displays, and building alongside people who deeply understand the problem you’re solving.

We’re a small, mission-driven team, which means your voice carries. You won’t be a ticket-taker — you’ll help shape the product, the architecture, and the company itself.

Why join

You will own the core technology of the device — from the piezo elements up — with real ownership, direct clinical impact, and the autonomy to set both the technical direction and the standard for the team around you.

Mellow Labs is an equal opportunity employer. We welcome applicants of all backgrounds and are committed to an inclusive hiring process.

Pay: $130,000.00 - $210,000.00 per year

Benefits:

• Flexible schedule
• Health savings account
• Paid time off
• Professional development assistance
• Stock options

Work Location: Hybrid remote in Mountain View, CA 94041