808nm IR Laser Diode Array System for 12-Well Cell Culture Plates

A complete hardware setup and 4-piece 3D-printed enclosure system designed to align an array of 808nm Near-Infrared (NIR) laser diodes over standard 12-well cell culture plates, powered by an LM2596 Constant-Current (CC) driver circuit.

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⚠️ Optical Safety Warning

• Wavelength: 808nm (Near-Infrared / Invisible to the naked human eye).
• Mandatory PPE: Laser safety glasses with certified optical density for 808nm (OD4+ or higher / EN 207 / ANSI Z136).
• Caution: Standard clear workshop safety goggles (e.g., ANSI Z87.1 / Z87+S) do not provide protection against direct or scattered infrared laser beams.

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🔬 Experimental Compatibility (12-Well Plate)

The top mounting fixture is engineered around the standard footprint of a 12-well cell culture plate ($3 \times 4$ matrix):

• Grid Capacity: Designed to hold up to 12 emitters.
• Current Configuration: Populated with 10 active 808nm laser diodes wired in series.
• Expandability: The remaining 2 positions are left unpopulated and can accommodate additional diodes in future revisions.

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🖨️ 3D Enclosure Structure

The enclosure consists of a modular 4-piece assembly:

1. Base Box (01_base_box.stl): Main structural body providing elevation and housing for the lower stages.
2. Internal Drawer (02_internal_drawer.stl): Sliding tray designed for easy insertion, positioning, and removal of the 12-well cell culture plate.
3. Laser Mounting Plate (03_laser_mount.stl): Alignment matrix positioned directly above the plate, securing the 5.6mm (TO-18) laser diode packages.
4. Top Cover (04_top_cover.stl): Upper protective lid enclosing the diode wiring and preventing external interference.

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⚡ Electrical Specifications & Power Circuit

The 10 laser diodes are wired strictly in series, ensuring that every emitter receives identical driving current.

Parameter	Specification
Laser Diodes	10x 808nm Infrared Laser Diodes (5.6mm / TO-18)
Forward Voltage ($V_f$) per Diode	~1.8V to 2.2V
Total Forward Voltage ($V_{total}$)	~18.0V to 22.0V
Operating Current ($I_f$)	250mA (0.25A Constant Current)
Current Regulation	LM2596 Step-Down Module (with CC/CV trimpots)
Power Supply Input	24V DC or 32V DC (1A minimum)

📌 Power Supply Note: Due to the internal dropout voltage of the LM2596 (~1.5V–2.0V), a 24V DC source operates near the upper voltage threshold required for 10 diodes in series (~22V). If the circuit fails to reach 250mA under full load, use a 32V DC power supply to provide adequate operating headroom.

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📌 Diode Pinout Reference (TO-18 / 5.6mm - Style C)

Viewed from the bottom (pins facing you, metal case notch positioned at the top):

               CASE NOTCH
                 (Top)
                   │
               ┌───┴───┐
            ──┤    ①    ├──
           /   \ (Anode) /   \
          │     \  (+)  /     │
          │      \     /      │
          │   ②   \___/   ③   │
          │(Cathode)    (PD)  │
          │  (-)              │
           \                 /
            ──┤             ├──
               └───────────┘