Hardware

Engineering for Trust: Material Selection in EverBowl Smart Pet Technology

Vinayak M K

18 Dec 2025 — 7 min read

Introduction: When End Users Have Four Legs

At Hoomanely, designing technology for pets presents unique engineering challenges that consumer electronics rarely encounter. Pets interact instinctively—through touch, taste, and repetition—without understanding operational boundaries or tolerating discomfort. When we developed EverBowl, every material decision was driven by a fundamental principle: the pet should never be aware of the technology.

This isn't marketing philosophy—it's engineering constraint. Materials must be biologically safe over years of exposure, stable under moisture and saliva, resistant to mechanical abuse, and support sophisticated sensing while remaining invisible to the animal. Today, I want to share how we approached material selection across plastics, metals, sensors, and electronics—balancing safety, durability, and performance for non-human users.

Design Philosophy: Four Critical Questions

Every material candidate for EverBowl answered four validation questions:

Biological Safety: Is it safe under long-term exposure to pets? (Licking, rubbing, proximity)

Environmental Stability: Does it remain stable under moisture, saliva, food acids, and cleaning cycles?

Mechanical Durability: Can it survive repeated impacts, dragging, and drops without degrading into unsafe fragments?

Functional Transparency: Does it support sensing and electronics without introducing thermal, acoustic, or visual disturbances?

Only materials passing all four criteria advanced to production. This filtering process shaped every component from structural plastics to optical windows.

Structural Plastics: Chemical Inertness and Mechanical Predictability

Selection Criteria

Plastics form EverBowl's structural backbone, but selection prioritized chemical stability over cost:

Food-Contact Safety: Any plastic with potential indirect exposure to food or water was verified as non-leaching and odor-neutral—no outgassing that pets could detect.

Impact Behavior: Brittle plastics eliminated early—materials that could chip into sharp fragments pose ingestion and injury risks.

Thermal Stability: Materials selected to tolerate warm water cleaning (60-70°C) without warping or surface degradation.

Acoustic Dampening: Internal structural plastics also serve vibration isolation—protecting sensor accuracy and preventing resonance pets might perceive as unsettling.

Engineering Trade-offs

Material Stiffness vs. Impact Absorption: Balance required between structural rigidity (dimensional stability for sensors) and impact resilience (survival of drops from counter height).

Surface Finish: Matte finishes preferred over glossy—reduces visual attraction, minimizes scratches that harbor bacteria, and dampens reflections that might distract pets.

Color Stability: Pigments selected for UV and moisture resistance—discoloration over time signals material degradation that could compromise safety.

Result: Structural plastics succeed through invisibility—no odors, no discoloration, no reaction from pets, and no measurable degradation after thousands of cleaning cycles.

Stainless Steel Bowls: Hygiene Through Material Properties

Why Stainless Steel?

Direct food and water contact demanded materials with inherent hygiene advantages:

Non-Porous Surface: Prevents bacterial absorption and biofilm formation—critical for daily feeding applications.

Chemical Inertness: Resists acids from wet food, oils, and typical pet food additives without corrosion or leaching.

Scratch Resistance: Maintains smooth surface integrity—scratches create micro-environments where bacteria multiply.

Thermal Neutrality: Avoids unexpected temperature sensations—pets are sensitive to thermal cues that affect feeding behavior.

Engineering Integration

Replaceable Interface Design: Steel bowls designed as removable, dishwasher-safe components—separates hygiene surface from embedded sensing system.

Mass Consistency: Stainless steel's predictable density and stiffness enable consistent weight measurements—material uniformity directly supports sensor calibration and accuracy.

Mounting Interface: Bowl positioning system designed for repeatable placement without mechanical stress on sensing load cells—tolerance stack-up analyzed to ensure ±0.5mm positional accuracy.

Benefit: Hygiene maintained through daily cleaning without compromising measurement precision or system longevity.

IR Illumination: Seeing Without Disturbing

Optical Emission Constraints

Infrared LEDs enable EverBowl's visual sensing without visible light intrusion, but introducing any optical emission into pet products requires careful engineering:

Non-Visible Wavelengths: 850nm IR wavelength selection—outside canine and feline visible spectrum, preventing distraction or stress.

Conservative Drive Current: IR LEDs operated at 60-70% rated maximum—prioritizes long-term stability (>50,000 hours) over peak output.

Thermal Management: Junction temperature maintained <60°C through PCB copper spreading and current limiting—ensures surface temperatures remain ambient.

Directional Confinement: Optical design includes baffles and controlled emission angles—light directed only toward target regions, preventing stray illumination.

Safety Validation

Ocular Safety: Emission intensity verified below IEC 62471 exempt group limits—no risk to pet or human eyes even during prolonged exposure.

Thermal Verification: Infrared thermal imaging confirms no hot spots >2°C above ambient on any surface accessible to pets.

Result: EverBowl "sees" pet interaction through IR imaging without any perceptible disturbance to the animal.

Proximity Sensors: Non-Contact Interaction Detection

Design Rationale

Physical contact sensors introduce multiple problems in pet environments:

Mechanical wear from repeated actuation
Debris accumulation in moving parts
Hygiene concerns from exposed surfaces
Potential pinch points or sharp edges upon failure

Solution: Time-of-flight (ToF) proximity sensors detect presence and distance without any physical contact requirement.

Material Integration Challenges

Sensor Window Requirements:

Optical transparency at sensor wavelength (940nm typical)
Scratch resistance from pet claws and cleaning
Saliva-safe materials (frequent licking expected)
Anti-reflective properties to prevent internal reflections

Housing Material Considerations:

Predictable optical properties (consistent transmission/absorption)
Black pigmentation to minimize stray light
Mechanical alignment stability through temperature and humidity cycling

Mounting System:

Survives cleaning vibration and impacts
Maintains sensor-to-target distance calibration
Isolated from bowl movement (prevents false triggers)

Benefit: Non-contact sensing eliminates wear surfaces, reduces hygiene concerns, and removes any mechanical interaction the pet could perceive as unusual.

Camera Systems: Observation Without Intrusion

Design Constraints for Pet Comfort

Camera integration in pet products requires balancing functional requirements with animal comfort:

No Visible Illumination: Camera operates in IR spectrum only—no LED indicators, no visible light, no flash.

No Audible Artifacts: Lens autofocus and sensor readout engineered for silent operation—mechanical noise can startle pets.

No Thermal Buildup: Camera module thermal design limits surface temperature rise to <1°C above ambient—prevents warm spots pets might investigate or avoid.

No Reflective Surfaces: Lens window and surrounding materials selected for matte finish—glossy surfaces attract visual attention.

Material Selection Impact

Lens Window: Optically clear polycarbonate with AR coating

Scratch-resistant (Mohs hardness 3)
Impact-resistant (survives 1m drop onto tile)
Hydrophobic coating (water beads off, reducing cleaning frequency)

Internal Mounting: Black ABS with ribbed geometry

Suppresses internal reflections
Dampens vibration from bowl impacts
Thermally isolates camera from warm electronics

Camera Bezel: Matte black finish recessed 1mm below surface

Visually invisible from pet's perspective
Flush design prevents debris accumulation
Cleaning-friendly (no crevices)

Result: From the pet's perspective, nothing is "watching"—the camera exists as a passive sensing instrument without any perceptible presence.

Environmental Resistance: Design for Real Pet Environments

The Reality of Pet Products

Pet products operate in conditions hostile to electronics:

Water spills: Daily occurrence
Saliva exposure: Constant through licking
Cleaning routines: Unpredictable chemicals and temperatures
Physical impacts: Bowls tipped, dragged, dropped

Design Philosophy: Materials must assume imperfect user behavior—occasional submersion, aggressive cleaning, and mechanical abuse are expected, not edge cases.

Holistic Material Protection Strategy

Sealed Interfaces: Gasket materials and compression sealing prevent capillary water ingress at all enclosure seams—validated through IP54 spray testing.

Corrosion Resistance: Where metal exposure unavoidable (fasteners, mounting points), stainless steel or zinc-plated hardware with conformal coating used.

Stable Elastomers: Silicone gaskets selected for:

Chemical resistance (cleaning agents, food acids)
Temperature stability (−20°C to +80°C)
Compression set resistance (maintains seal over thousands of cycles)

Surface Treatments: Enclosure plastics include:

Anti-microbial additives (silver-ion based, FDA-approved)
Hydrophobic surface treatment (reduces residue adhesion)
UV stabilizers (prevents photo-degradation in sunlit environments)

Maintainability Preserved: Environmental protection achieved without creating sealed, non-serviceable units—modular design allows disassembly for deep cleaning and component replacement.

Mechanical Isolation: Protecting Sensors and Pet Comfort

The Vibration Challenge

High-precision sensors (load cells, accelerometers) require stable mounting, but pets generate constant vibration through footsteps, bowl impacts, and floor-transmitted noise.

Solution: Multi-layer isolation strategy using material properties:

Primary Isolation: Elastomer mounts (Shore A 40-60 durometer) decouple sensor assembly from enclosure structure—attenuates vibration above 50Hz by >20dB.

Secondary Isolation: Internal sensor PCBs mounted on compliant standoffs—prevents high-frequency resonance from floor vibration.

Damping Materials: Strategic placement of viscoelastic damping pads at structural joints—dissipates vibrational energy without introducing compliance that affects measurements.

Pet Comfort Through Silence

Mechanical isolation serves dual purpose:

Sensor Accuracy: Eliminates false readings from environmental vibration
Pet Comfort: Prevents any tactile feedback (buzzing, humming) that pets might find unsettling

Validation: Accelerometer testing confirms no measurable vibration >1g at frequencies <200Hz transmitted to pet contact surfaces—below canine tactile sensitivity threshold.

Result: EverBowl is mechanically inert from the pet's perspective—no unusual vibration, no acoustic feedback, no sensation that differs from a conventional bowl.

Longevity and Aging: Safety Over Time

Material Degradation as Safety Risk

Materials safe on day one can become hazardous after months of use if they:

Crack and create sharp edges
Leach chemicals after UV/temperature exposure
Loosen mechanically and create ingestion hazards
Change surface properties (become sticky, brittle)

Design Approach: Material selection prioritized long-term behavior over initial performance.

Accelerated Aging Validation

UV Exposure: 1000 hours xenon arc lamp (equivalent to 2 years sunlight exposure)—no embrittlement, color shift <ΔE 2.0

Thermal Cycling: 100 cycles −20°C to +60°C—no cracking, warping, or seal degradation

Chemical Resistance: 500 cleaning cycles with common detergents—no surface roughness increase, no material swelling

Mechanical Fatigue: 10,000 simulated impacts (bowl dropped from 30cm height)—no crack initiation, no sharp edge formation

Failure Mode Analysis: Even at end-of-life, materials designed to degrade gracefully:

Plastics may discolor but remain structurally sound
Gaskets may lose compression but don't fragment
Electronics fail-safe (loss of function, not hazardous output)

Result: EverBowl maintains safety profile throughout intended 5-year service life.

System Integration: Materials Working Together

Holistic Material Strategy

EverBowl's safety and performance emerge from material system design, not individual component selection:

Structural Hierarchy:

Plastics: Structural support, vibration isolation, optical properties
Steel: Hygiene interface, mass reference for sensing
Optics: Non-intrusive sensing, controlled emission
Electronics: Hidden, thermally managed, moisture-protected
Surfaces: Neutral texture, color, temperature—pet-first design

Interface Compatibility: Every material boundary analyzed for:

Thermal expansion mismatch (prevents stress cracking)
Galvanic corrosion potential (dissimilar metals separated)
Chemical compatibility (no material-to-material degradation)
Acoustic coupling (vibration paths intentionally designed)

Validation: System-level testing confirms materials perform not just individually, but as integrated assembly under real-world conditions.

Conclusion: Invisible Technology Through Material Excellence

At Hoomanely, material selection for EverBowl wasn't driven by cost or convenience—it was guided by responsibility to pets who cannot voice discomfort or concerns. Every material was validated for safety, stability, durability, and invisibility.

The result is a smart pet bowl where technology recedes completely. Pets interact with food-safe surfaces, comfortable textures, and familiar forms. The sophisticated sensing, processing, and connectivity exist beneath a material layer engineered specifically to be unremarkable.

This is engineering for trust—where the highest achievement isn't features the user notices, but safety and comfort they never question. Materials are where that trust begins, and for products serving pets, there are no compromises.