Seahorse ROV MVP 1 Visual Reference

Body & Propulsion — SVG Reference

Structural diagrams for the biomimetic seahorse underwater ROV. Segment geometry, side-mounted eye sockets with dome viewports and fisheye lenses, 940nm NIR stealth vision, electrochemical mineral armor (EMA), fin propulsion layout, prehensile tail mechanism, energy harvesting integration, and impact behavior. Use as starting geometry for CAD / 3D print prototyping and AI image model reference.

← System Design

01 — Segment Cross Section (Head Variant — with Eye Sockets)

Head segments: 4 L-shaped plates with eye sockets on left and right walls. Dome viewports (acrylic hemisphere) house 190°+ fisheye lenses in curved plate surfaces. Dorsal fin ray on top, ballast rail on bottom. Body/mid/tail segments omit eye sockets but keep same plate geometry.

mineral crust (EMA aragonite) SEALED SPINE RIDGE MG90S FIN RAY solar BALLAST RAIL o-ring A B C D LEFT EYE dome + fisheye 940nm NIR ring RIGHT EYE dome + fisheye 940nm NIR ring ~40mm (head) → ~15mm (tail) PETG core + mineral crust (EMA) · NoIR cameras · 940nm stealth ↑ DORSAL (top) ↓ VENTRAL (bottom)
Plate A
Plate B
Plate C
Plate D
Sealed spine
Fin ray mount
Eye sockets (head seg only)

02 — Side Profile — Full ROV Layout

Tapering segments from head to tail. Dorsal fin array runs along the top ridge. Electronics distributed by zone. Tether exits at tail. Ballast on ventral rail.

~ water surface ~ DORSAL FIN ARRAY 8 MG90S servos · carbon fiber rays · silicone membrane SOLAR CELLS (between rays) LEFT EYE dome + fisheye 940nm RIGHT EYE (far side) 190°+ pectoral MINERAL ARMOR (EMA) TETHER to surface T grip pads (inner) tendon cable adjustable ballast (ventral rail) HEAD Side-mount Eyes · Servos · LEDs BODY Pi 5 · IMU · Depth · PCA9685 MID Battery · BEC · Buoyancy TAIL Prehensile Grip · Turbine · Tether ── sealed spine channel ── ~250–350mm total length Operating depth: 1–10m · Fresh + Salt · EMA mineral crust · 940nm NIR stealth
Head — Side-mounted eyes + 180° rotation
Body — Compute + sensors
Mid — Power + buoyancy
Tail — Prehensile grip + turbine
Dorsal fin array
Sealed spine
Solar cells

03a — Gliding Joint (Intra-Segment)

Plates slide on impact. O-ring seal at overlap prevents water ingress.

o-ring seal A B Slides on impact O-ring maintains seal under compression

03b — Pivot Joint (Inter-Segment)

TPU flex zone between segments. Allows body articulation for swimming.

TPU ~15° flex Seg N N+1 TPU 95A living hinge Waterproof + flexible Aids undulating swim motion

04 — Camera Head — Side-Mounted Eyes (True Seahorse Anatomy)

Dual IMX219 cameras with 190°+ fisheye lens adapters sit in side-mounted eye sockets — like a real seahorse. Dome viewports (acrylic hemisphere) seal each socket while preserving the wide FOV. Dual pipeline: VR180 immersive stream + OpenCV stereo depth mapping from dewarped overlap zone.

MODE A — VR180 + DEPTH fisheye stereo · immersive + depth map HEAD → body STEREO OVERLAP baseline = head width L R FORWARD ↑ VR180 IMMERSIVE + DEPTH MAPPING Primary mode · headset or phone MODE B — PANORAMIC VR full fisheye FOV · ~330° combined HEAD ~330° COVERAGE (fisheye overlap) ← L R → FULL SURROUND VR LOOK-AROUND No depth · software-only mode switch MODE C — DEPTH OVERLAY dewarped stereo · phone flat view HEAD FWD ↑ REAR ↓ depth map PHONE APP WITH DEPTH OVERLAY OpenCV SGBM on dewarped region FRONT VIEW — Eye Socket Detail dome viewport + fisheye lens in curved head wall dome viewport FE IMX219+fisheye dome viewport FE IMX219+fisheye spine LEDs (forehead) ↑ dorsal ↓ ventral o-ring 190°+ FOV STEALTH: 940nm NIR — invisible to fish Dome acrylic viewport preserves 190°+ fisheye FOV underwater. No rotation servo needed — fisheye covers full hemisphere per eye. Dual pipeline from each camera: VR: fisheye → equirect → PiCam360 Depth: dewarp overlap → OpenCV SGBM O-ring sealed dome, M12 fisheye mount

05 — Dorsal Fin Wave Propagation

Sine wave propagates along fin ray array. 8 MG90S servo-driven carbon fiber rays connected by silicone membrane. Frequency = speed, amplitude = power, direction = forward/reverse. Silent propulsion — won't spook fish.

dorsal ridge housing (32mm tall, tapered) MG90S servo 22.5 x 12.2 x 28mm solar cells 0° 45° 90° MAX 135° 180° 225° 270° MAX 315° fin ray 25mm + ridge 32mm servo horn r=10mm carbon fiber rod 1.5mm dia, tapered silicone membrane 0.5mm, translucent WAVE PROPAGATION → THRUST FORWARD reverse wave direction = reverse thrust segments 5, 7, 9, 11, 13, 15, 17, 19 — spacing every 2 segments 8 SERVO-DRIVEN FIN RAYS MG90S microservos · carbon fiber rays · silicone membrane · solar cell pockets between rays

06 — Impact Behavior — Underwater Collision

Bumping rocks, submerged structure, or launch impact from shore. Plates slide, spine stays sealed. Electronics and cameras protected.

NORMAL mineral crust (EMA) fin ray SEALED 100% width → ROCK IMPACT ~50% COMPRESSED SAFE ✓ spine + o-rings intact mineral absorbs → PETG holds

07 — Buoyancy System — Dual Water Compensation

MVP 1: manual adjustable ballast weights. Future: active syringe pump buoyancy engine. Saltwater = more buoyant (add weight), Freshwater = less buoyant (remove weight).

FRESHWATER — 1.0 g/cm³ ROV body EMA crust 0.5–1mm light ballast neutral SALTWATER — 1.025 g/cm³ ROV body EMA crust 1.5–2.5mm reduced ballast (mineral = 2.9 g/cm³) more buoyant Mineral crust = integrated ballast · same plates, different soak time Future: Active syringe pump auto-compensates ±2.5% density difference

08 — Prehensile Tail — Anchor-Observe-Release Cycle

Tendon-driven curling tail grips structure for zero-power station keeping. One servo, two cables. Fail-safe: power off = slack tendon = auto-release + float to surface.

TRANSIT — Tail Straight tendons relaxed · streamlined body SERVO tendons (slack) turbine ANCHORED — Tail Curled tendon pulled · gripping structure body PULL submerged branch grip pads (ridged TPU) FSR (touch) tendon (taut) FAIL-SAFE power off = auto release seahorse FLOAT ↑ Power loss → Servo de-energizes → Tendon goes slack → Tail uncurls → Positive buoyancy → Float to surface ✓ PATROL BEHAVIOR LOOP TRANSIT → APPROACH → ANCHOR → PATROL → RELEASE repeat at next structure

09 — Energy Harvesting — Solar + Hydro Turbine Layout

Solar cells between dorsal fin rays. Micro turbine in tail funnel. When anchored in current, tail simultaneously grips AND funnels water through the generator. MPPT controller manages both inputs.

SUN 40-60% at 1-2m depth 8 FIN RAYS (seg 5-19) SOLAR CELLS (between fin rays) ~0.5-1W total water flow → TURBINE ~100-200mW in current HEAD MPPT CONTROLLER BQ25570 · manages both inputs solar in turbine in 2S LiPo 2200mAh trickle charge PATROL MODE ENERGY MATH Draw: ~2-3W (incl. 940nm NIR ~0.2W) Harvest: ~0.5-1.2W · Net: ~1-2W → 8-12hr+ runtime Ideal conditions: near energy-neutral ✓

10 — Mineral Armor — Electrochemical Mineral Accretion (EMA)

Biorock-inspired ceramic armor. Low-voltage DC current through conductive-coated PETG plates in mineral electrolyte deposits aragonite (CaCO₃) / brucite (Mg(OH)₂) ceramic crust. Self-healing by re-soaking. Mohs hardness 3.5–4. Density 2.9 g/cm³ doubles as integrated ballast.

PLATE WALL CROSS-SECTION layers from core to surface PETG CORE 2.0 mm wall · structural conductive coat ~20μm MINERAL CRUST (EMA) 0.5–2.5 mm aragonite / brucite 2mm total 2.5–4.5mm HARDNESS Mohs 3.5–4 aragonite ceramic DENSITY 2.9 g/cm³ integrated ballast UV RESISTANCE Excellent natural mineral SELF-HEALING Re-soak to repair sacrificial armor BEFORE / AFTER MINERALIZATION BARE PLATE PETG smooth UV vulnerable → 48–168hr soak MINERALIZED PETG + mineral armored UV proof ballasted ELECTROLYTE BATH — EMA DEPOSITION low-voltage DC in mineral electrolyte mineral electrolyte ANODE Ti mesh + CATHODE plate mineral forming ANODE Ti mesh + DC SUPPLY — 6V / 2 A/m² − KEY ADVANTAGES: • Sacrificial armor — re-grow by re-soaking • Same plates, diff soak time → FW/SW ballast • Acoustic dampening (denser surface) • Natural camouflage (mineral texture) • UV protection for PETG underneath Setup: ~$130 one-time · Per-plate: ~$0
3D Print + EMA Notes: Rigid segments in PETG/ASA (UV + saltwater resistant) at 0.2mm layers, 1.5–2mm wall thickness. Flex joints in TPU 95A. Spine channel ≥10mm inner diameter for tether + tendon cables + flex wiring. Tail inner surfaces: ridged TPU grip pads (0.5mm rib spacing). All fasteners 316 stainless steel. Rinse with fresh water after every saltwater session. Solar cell recesses in dorsal surface between fin ray mounts (0.8mm depth pocket for flush-mount flex cells). Mineral Armor (EMA): After printing, apply conductive coat (graphite/nickel spray), then soak plates in mineral electrolyte at 6V DC. 48–168hr soak = 0.5–2.5mm aragonite/brucite ceramic crust. Thicker crust for saltwater (integrated ballast), thinner for freshwater. Damaged crust re-grows by re-soaking — sacrificial armor. O-ring seal surfaces must be masked before EMA deposition.
Reference: UCSD — Seahorse Armor Research · McKittrick & Meyers · Acta Biomaterialia, 2013