Q1. What does Posifa Technologies specialize in?
Posifa Technologies designs and manufactures MEMS-based thermal sensing solutions for measuring mass flow, gas concentration, vacuum pressure, and air velocity across diverse industries — including medical oxygen therapy, hydrogen energy, HVAC/refrigeration, and industrial process control.
Our proprietary MEMS platform integrates a micro-heater, temperature-sensing thermopiles, and calibration circuitry onto a single silicon die. This monolithic design eliminates moving parts, ensuring millisecond-level response time, repeatable accuracy, and long-term drift < 0.5% F.S., even under high humidity and pressure cycling.
Q2. What differentiates Posifa sensors from other MEMS and non-MEMS solutions?
Posifa’s competitive advantage lies in its thin-film thermopile technology and proprietary laminar-flow channel architecture, providing superior performance at low flow rates (< 1 SLM) where traditional hot-film or ultrasonic sensors lose linearity.
Compared with thick-film or wire-based designs, Posifa’s MEMS sensors:
- Deliver 10–50× faster response times (as low as 5 ms).
- Require no periodic recalibration, unlike catalytic or electrochemical sensors
- Are resistant to condensation, shock, and vibration.
- Offer modular scalability, allowing seamless integration into compact medical or HVAC assemblies.
These capabilities make Posifa sensors a high-value alternative to legacy flow-measurement systems from Sensirion, Honeywell, Amphenol, and MKS Instruments, especially in cost-sensitive, safety-critical environments.
Q3. Where are Posifa sensors designed and manufactured?
All Posifa MEMS die and modules are developed at our Silicon Valley R&D headquarters, with production through ISO 9001 and UL certified labs in Asia.
This ensures full traceability and supply-chain scalability for customers in medical, hydrogen, and energy verticals.
Q4. Does Posifa support custom OEM sensor development?
Yes. Posifa provides application-specific MEMS sensor co-development — from custom flow-channel geometries and analog front-end design to integrated signal conditioning and calibration routines.
Our engineering team works directly with OEM R&D to optimize dynamic range, accuracy, and gas compatibility while maintaining manufacturability and cost efficiency.
MEDICAL & RESPIRATORY APPLICATIONS
Q1. Which Posifa sensors are used in oxygen concentrators, ventilators, and anesthesia devices?
Posifa’s PMF5000 and PMF82000 series MEMS thermal mass-flow sensors are optimized for respiratory devices requiring high precision at low differential pressures and micro-flow conditions.
They feature:
- Accuracy: ±1% F.S. (0–25% range) and ±4% reading (25–100%)
- Response Time: 5 ms typical
- Drift: < 0.5% F.S. over multi-year use
- Output Interfaces: 1–5 V analog, I²C digital
These sensors are factory-calibrated for air and oxygen mixtures and used in portable oxygen concentrators (POC), CPAP/BiPAP systems, and anesthesia vaporizers.
Q2. Why is low-flow accuracy critical in medical oxygen systems?
Unlike industrial flow, medical oxygen therapy involves pulsed flow patterns triggered by the patient’s inhalation effort.
At low flow rates (< 1 SLM), even slight sensor inaccuracies can cause:
- Premature or delayed oxygen pulses
- Unstable dosing under sleep or variable breathing cycles
- Inefficient battery use and perceived discomfort
Posifa’s MEMS sensors achieve stable linearity down to 0.05 SLM through advanced thermal isolation and ultra-fast signal conditioning, ensuring breath-synchronized delivery with sub-10 ms latency.
Q3. How do Posifa sensors compare with ultrasonic transit-time sensors in POCs
Ultrasonic sensors measure transit time differences of acoustic pulses. While they can sense both O₂ concentration and flow, they suffer at low-flow regimes and high humidity.
In contrast, Posifa’s MEMS thermal architecture:
- Directly measures mass flow, independent of gas type correction factors.
- Operates reliably under condensation or vibration.
- Consumes < 30 mA power, ideal for battery-powered POCs. Ultrasonic sensors remain advantageous for dual measurement (O₂ + flow) — a capability Posifa is integrating into its next-generation module launching by end of 2025.
Q4. What is the long-term stability and lifecycle of Posifa medical sensors?
Posifa’s PMF and PMA medical sensors undergo accelerated aging and thermal cycling validation equivalent to 5 years of operation. MEMS construction eliminates mechanical drift, ensuring repeatable output across millions of inhalation cycles. Customers typically deploy the sensors for > 20,000 hours of active use without recalibration, maintaining stable performance within ±1% drift.
HYDROGEN & FUEL CELL APPLICATIONS
Q1. What hydrogen sensing technology does Posifa use?
Posifa’s PGS4000 series uses MEMS catalytic thermal conductivity detection optimized for hydrogen’s high diffusivity.
The design incorporates a micro-heater and temperature-sensitive resistor bridge sealed on a silicon substrate, enabling fast, selective detection of H₂ against ambient gases.
Key specs:
- Response Time: < 0.1 s (10× faster than FIS/Nissha-type sensors)
- Maintenance: No periodic calibration required
- Lifetime:> 5 years under continuous use
This makes PGS4000 ideal for fuel-cell vehicles, hydrogen storage, and electrolyzer leak detection systems.
Q2. How does the sensor ensure accuracy under varying humidity and temperature?
The MEMS architecture features dual thermal detection channels for active ambient compensation.
This differential measurement cancels temperature and humidity drift, maintaining sensitivity across –20 °C to +80 °C with minimal zero-shift (< 1% F.S.).
Q3. What are the key benefits over electrochemical or catalytic-bead sensors?
- No catalyst aging: MEMS heater design prevents poisoning and oxidation.
- Fast recovery: Responds within milliseconds even after high concentration exposure.
- Digital signal conditioning: Provides linear analog/digital output proportional to concentration, enabling direct integration with ECU or PLC systems.
HVAC / REFRIGERATION / A2L LEAK DETECTION
Q1. What role do Posifa sensors play in A2L refrigerant safety?
The shift toward A2L low-GWP refrigerants like R32 and R1234yf demands fast, low-cost leak detection to comply with ASHRAE 15, UL 60335-2-40, and EPA 608 standards.
Posifa’s MEMS gas sensors detect minute refrigerant leaks (< 25 ppm) in real time, supporting distributed multi-point detection for HVAC and refrigeration OEMs.
Q2. Why are MEMS sensors superior to electrochemical alternatives for A2L detection
Electrochemical sensors degrade with exposure and need frequent recalibration. Posifa’s MEMS thermal detectors:
- Offer zero drift over > 3 years continuous operation.
- Are immune to cross-sensitivity with hydrocarbons and humidity
- Require no consumable elements, reducing maintenance costs.
- They can be embedded directly into evaporator coils, VRF systems, and smart HVAC controllers
Q3. How do Posifa airflow and differential pressure sensors improve HVAC energy efficiency?
The PAV3000 and PMA1000 series measure air velocity and static pressure with precision better than ±3% reading.
Accurate feedback allows intelligent fan control and optimized airflow distribution, cutting energy consumption by up to 25% in building automation systems.
BATTERY SAFETY & THERMAL MANAGEMENT
Q1. How do Posifa sensors contribute to EV and ESS battery safety?
Posifa’s MEMS pressure and flow sensors detect internal pack venting, gas release, or abnormal air circulation — providing early warning for thermal runaway prevention.
Their sub-millisecond detection speed allows integration with Battery Management Systems (BMS) to trigger isolation or cooling events before ignition.
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Q2. What environmental durability do these sensors offer?
All battery-safety sensors undergo qualification for automotive-grade thermal cycling (–40 °C to +125 °C), vibration, and EMC immunity.
The MEMS sensor element remains stable in corrosive or humid conditions, critical for EV packs, energy storage containers, and hydrogen hybrid systems.
DATA CENTER COOLING & AIRFLOW MONITORING
Q1. How are Posifa airflow sensors used in data centers?
Posifa MEMS airflow sensors monitor air velocity and differential pressure in hot/cold aisles, enabling adaptive fan control and preventing localized hotspots.
By maintaining balanced cooling, they help operators cut energy costs and improve uptime reliability across server racks and cooling systems.
Q2. What integration interfaces are supported?
Sensors offer analog voltage, I²C, and UART outputs for connection with DCIM, BMS, or environmental monitoring systems.
Optional calibration ensures consistent readings under variable humidity and particulate loads.
VACUUM & INDUSTRIAL PROCESS CONTROL
Q1. What is the principle behind Posifa’s MEMS Pirani vacuum sensors?
Posifa’s PVC4000 and PVC5000 series measure gas pressure based on thermal conductivity within a micromachined cavity.
As gas density decreases, the rate of heat dissipation changes — allowing precise vacuum measurement from 1 × 10⁻³ Torr to atmospheric pressure.
Advantages include:
- Fast thermal equilibrium (< 30 ms)
- Long-term drift < 1% F.S.
- Compact TO-5 or SMD packaging for OEM integration in semiconductor tools, HVAC, and food packaging systems.
Q2. How do Posifa Pirani gauges compare with conventional wire-type sensors?
Traditional Pirani sensors use fragile tungsten filaments prone to breakage and contamination.
Posifa’s solid-state MEMS heater/thermopile eliminates mechanical fragility, offering superior vibration resistance and longer lifetime under thermal cycling.
CUSTOM DEVELOPMENT & PARTNER INTEGRATION
Q1. Can Posifa co-develop OEM modules or sensor subsystems?
Yes. Posifa collaborates with OEMs to design application-specific sensor modules, combining flow, gas, or pressure sensing into compact packages.
Capabilities include multi-parameter calibration, embedded signal processing, and cross-sensitivity compensation, ensuring plug-and-play system integration.
Q2. What post-deployment support is available?
Posifa provides ongoing engineering support, calibration data retention, and firmware optimization for long-term reliability and regulatory validation.
Our R&D teams also help OEMs align sensor specifications with FDA, CE, and automotive compliance frameworks, depending on the application.