Ultrasonic fingerprint sensors have gained popularity due to their advanced security and ability to read through contaminants like moisture or dust. However, no technology is flawless. Below, we dive into the key disadvantages of ultrasonic fingerprint sensors—highlighting points that may influence manufacturers, developers, and end‑users.
1. Higher Cost and Limited Availability
Compared to capacitive or optical sensors, ultrasonic modules require more complex hardware (such as piezoelectric transducers) and precision engineering. This complexity increases manufacturing costs, which often leads to positioning ultrasonic sensors mainly in premium devices . As a result, adoption in budget‑oriented products remains limited.
2. Slower Response Time
The mechanism of sending ultrasonic pulses and interpreting a 3D image can introduce latency. While the delay is often minimal, perceptive users may notice a longer unlocking time compared to the near-instant results of capacitive readers .
3. Skin and Biological Variability
Not all fingerprints are equally readable. Individuals with dry skin, very shallow ridges, scars, or certain dermatological conditions may face inconsistent sensor performance—even on advanced ultrasonic systems . Industry reports suggest that a non-negligible share of users—sometimes labeled “goats”—consistently experience matching issues regardless of sensor type .
4. Environmental Sensitivity and Interference
Despite ultrasonic sensors’ resilience against dirt and moisture, they remain vulnerable to external environmental factors:
Surface contamination: Excessive oils, debris, or even screen protectors (especially thick or non-conductive types) can impair ultrasonic pulse transmission :contentReference.
Temperature and humidity: Changes in ambient conditions can affect the speed and behavior of sound waves, diminishing accuracy or suggesting recalibration :contentReference.
Size & power demands: The hardware footprint and energy requirements may impact battery life or force trade‑offs in compact form factors :contentReference.
Screen protector compatibility: Some protective layers can block or distort ultrasonic waves, leading to failed attempts :contentReference.
6. Adoption Lag and Ecosystem Constraints
While ultrasonic fingerprint sensors offer compelling advantages, they are not yet ubiquitous. Their presence is largely confined to high-end models (e.g., select Samsung phones), limiting consumer exposure and ecosystem support .
Summary Table of Disadvantages
Disadvantage
Impact
Higher cost
Premium device pricing limits widespread adoption
Slower response
Perceived lag compared to capacitive sensors
Skin compatibility issues
Inconsistent performance for certain users
Environmental sensitivity
Performance affected by contaminants and conditions
Integration challenges
Hardware/practical constraints in design
Limited adoption
Less ecosystem maturity and awareness
Conclusion
Ultrasonic fingerprint sensors showcase impressive advancements—especially in security and reliability under dirty or wet conditions. Yet, their disadvantages are meaningful: higher cost, slower response time, biological variability among users, environmental sensitivities, and integration hurdles. Brands and users alike must weigh these factors against benefits when deciding whether ultrasonics fit their use case and budget. As manufacturing matures and adoption grows, some of these drawbacks may diminish—yet awareness remains key today.
