Brushless vs Brushed Vibration Motors: Which Is Right for Your Device?

When selecting vibration motors for compact devices, the choice between small BLDC motors (5mm-12mm diameter) and micro brushed motors (7mm-12mm diameter) can define product performance, lifespan, and user experience. Both convert electrical energy into rotational motion to generate vibration, but their design differences create distinct advantages for specific applications. Below is a comprehensive comparison to guide your decision—plus insights into our custom motor solutions.

Core Structural Differences

The fundamental distinction lies in how each motor achieves commutation (current direction control), which impacts durability, efficiency, and complexity.

Micro Brushless Motors (5mm-12mm)

These motors eliminate the carbon brushes and mechanical commutator found in traditional designs. Instead, they rely on electronic controllers and Hall sensors to regulate current flow to the stator windings. Key structural features include:

• Stator-rotor configuration: A stationary stator with permanent magnets and a rotating coil-wound rotor (or vice versa in some designs).

• Integrated electronics: Many small BLDC motors embed driver ICs, simplifying integration with device PCBs without electromagnetic interference.

• Material advancements: High-performance Nd-Fe-B magnets and aluminum alloy shells boost power density and heat dissipation.

The brushless design eliminates physical contact between moving parts, reducing friction and wear—a game-changer for long-term reliability.

Micro Brushed Motors (7mm-12mm)

A century-old technology, these motors use a straightforward mechanical system:

• Carbon brushes + commutator: Brushes transfer current to the rotor’s electromagnets by sliding against a segmented commutator, which flips current direction to sustain rotation.

• Simplified construction: Fewer components (no sensors or controllers) lower manufacturing costs but limit performance.

• Core variations: Some brushed motors feature coreless rotor designs (cup-shaped coils) to reduce inertia, though they still rely on precious metal brushes for commutation.

While affordable, the brush-commutator interface creates inherent limitations in lifespan and efficiency.

Size & Form Factor Comparison

Both motor types target compact applications, but their size ranges and design flexibility differ:

Micro Brushless Motor Dimensions

• Diameter range: 5mm to 12mm (e.g., 5mm×2.5mm pancake-style motors).

• Thickness advantage: Ultra-slim profiles (as low as 1.8mm) make them ideal for wearables and thin devices like smartwatches.

• Mounting versatility: Options for adhesive, lead wire, FPCB, or spring mounting to fit constrained spaces.

At the 5mm end, mini brushless motors are the smallest viable vibration solution for micro-robots and implantable medical devices.

Micro Brushed Motor Dimensions

• Diameter range: 7mm to 12mm (limited by the need to fit brushes and commutators).

• Typical profiles: Coin-style brushed motors (e.g., 8mm×2.0mm) dominate this category, with fixed lead wire or connector-based mounting.

• Size constraints: Brushes require minimum internal clearance, preventing diameters smaller than 7mm without sacrificing performance.

Brushed motors offer fewer size options but remain competitive for mid-range compactness needs.

Vibration Performance: What Matters Most?

Vibration effectiveness depends on amplitude (g-force), consistency, noise, and response time—areas where brushless technology excels, with brushed motors holding niche advantages.

Micro Brushless Motors

• Efficient vibration output: Higher energy efficiency (70%+ typical) translates to more vibration per watt, with 12mm models delivering up to 2.0g amplitude at 9,000 RPM.

• Smooth, quiet operation: No brush friction means minimal acoustic noise (often <45dB) and reduced electromagnetic interference—critical for wearables and medical devices.

• Rapid response: Coreless and slotless designs (common in small BLDC motors) have low rotational inertia, enabling rise times <90ms and precise vibration control.

• Consistent performance: No brush wear means vibration force remains stable over the motor’s 20,000+ hour lifespan.

Micro Brushed Motors

• High startup torque: Mechanical commutation delivers stronger initial vibration, useful for devices needing immediate haptic feedback (e.g., pagers).

• Lower efficiency: Friction losses reduce output, with 12mm models consuming 48-150mA at 3V (vs. 30mA for comparable brushless units).

• Inconsistent lifespan: Brushes wear out after 1,000-5,000 hours, causing declining vibration force and increasing noise.

• Electrical interference: Brush arcing generates EMI that can disrupt nearby sensors or circuits.

Application Scenarios: Match the Motor to Your Device

Your use case’s priorities—cost, lifespan, size, or precision—will dictate the best choice.

Where to Use Micro Brushless Motors

These motors shine in high-performance, long-lifespan applications:

• Wearable tech: Smartwatches and fitness trackers benefit from 5-8mm mini brushless motors’ slim profiles and quiet operation.

• Medical devices: Surgical tools and portable monitors rely on 10-12mm small BLDC motors’ precision and 20,000-hour lifespan.

• Industrial sensors: Detectors and scanners use brushless vibration for consistent feedback in harsh environments (-30℃ to 85℃).

• Smart home devices: IoT sensors and compact appliances leverage efficient, low-EMI micro brushless motors.

Where to Use Micro Brushed Motors

Brushed motors excel in cost-sensitive, short-to-mid-lifespan products:

• Consumer electronics: Low-cost toys, remote controls, and disposable devices prioritize 7-10mm brushed motors’ affordability.

• Entry-level haptics: Basic pagers and budget fitness bands use 12mm coin brushed motors for simple vibration alerts.

• Disposable medical tools: Single-use devices (e.g., insulin pens) don’t require the long lifespan of brushless models.

Our Custom Motor Solutions

Whether you need a 5mm micro brushless motor for a hearing aid or a 12mm brushed motor for a toy, we offer end-to-end customization:

• Performance tuning: Adjust voltage (1.8V-4V), amplitude (0.5g-2.0g), and RPM (5,000-50,000) to match your device’s specs.

• Form factor flexibility: Customize leads (wire, FPCB, or spring), connectors (JST, Molex), and mounting (adhesive, bolt-on).

• Quality assurance: Every motor undergoes 4-point testing (performance, waveform, noise, appearance) and 200% pre-shipment inspection.

• Rapid prototyping: Our 80 million-unit annual capacity ensures fast turnaround for custom orders.

Ready to Choose? We’re Here to Help

The decision boils down to priorities: micro brushless motors for longevity, precision, and efficiency; micro brushed motors for cost savings in short-lifespan devices. Whatever your needs, our custom solutions ensure a perfect fit for your 5mm-12mm application.

Need small BLDC motors, micro brushless motors, or custom brushed vibration motors? Contact our factory today for a free quote.