Carbon nanomaterial networks help flexible pressure sensors turn deformation into an electrical signal. In a piezoresistive sensor, pressing the device changes connections and gaps in a conductive network, which changes its resistance. But carbon material alone does not determine how a sensor works: flexible devices may instead use capacitive, piezoelectric, or triboelectric mechanisms.
How do carbon nanotubes make a pressure sensor work?
Carbon nanotubes (CNTs) can form a conductive network within a flexible material or across its surface. When pressure bends or compresses the structure, the distances between nanotubes and their contact points can change. That can alter the number and quality of conductive paths through the network.
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In a piezoresistive design, the sensor measures the resulting change in electrical resistance. A 2024 modeling study of CNT–elastomer composites describes deformation-dependent percolation pathways: as the composite changes shape, the routes available for electrical conduction change too. Elsevier’s 2024 study examines this relationship.
What changes inside a flexible pressure sensor when you press it?
The flexible support deforms, and the conductive network responds to that deformation. Depending on the material and structure, nanotubes may move closer together or farther apart, make or lose contact, or change the paths available for current. The sensor converts those physical changes into a measurable electrical response.
#1 Best Overall
- 【Material Structure】The pressure sensor display module is made of copper clad laminate, and the display screen is made of plexiglass, with clear, accurate, efficient, beautiful and readings.
- 【Size Parameters】The module size is about 32 x 62.6 x 11 mm, the baud rate is 9600, the data length is 8 bits, the stop bit is 1 bit, no parity, for RP-C series pressure sensors.
- 【USB Charging】Low power consumption pressure sensor, powered by lithium battery, long battery life, can be charged by mobile phone charger, charging current is 50mA, charging time is about 3.5 hours.
- 【Functional Use】The pressure sensor display module is small in size, easy to carry and store, and is often used in the measurement and display of flexible sensors (flexible, thin-film pressure, force sensors).
- 【Accurate Measurement】Strict quality control and quality assurance, high safety factor, can be used without worry, ultra-high sensitivity can ensure accurate measurement results.
Porous structures add another part to the process: their internal spaces can compress under load, rearranging the conductive network. For example, a 2022 Royal Society of Chemistry study describes a CNT network dip-coated onto a porous elastomer sponge for a piezoresistive sensor. The sponge’s structure and the network’s rearrangement are part of how pressure produces a signal, not just incidental packaging. Read the 2022 study.
Which carbon materials and structures are used?
Research on flexible pressure sensors includes carbon nanotubes, graphene, and carbon black. These materials can have different roles: a carbon material may form the active sensing network, or it may serve as a compliant electrode in a device whose sensing mechanism is different. A 2025 Royal Society of Chemistry review discusses graphene’s use in both roles. See the 2025 review.
Rank #2
- High-quality materials: The flexible film pressure sensor is made of polyester film with excellent mechanical properties, high-conductivity materials, and nano-scale pressure-sensitive material. The top layer is a flexible film with a pressure-sensitive composite; the bottom layer is a flexible film with printed conductive traces. Ideal for Arduino prototyping, sleep monitoring, smart footwear, pressure switches, counters, medical devices, robotics, and industrial process control.
- Durable & stable: Tested with a 2 kg weight impact, rated for millions of cycles. Low drift and tight tolerance: individual sensor resistance ±3%. Activation time <0.01 s; response time <10 ms. Trigger force ≈20 g. Default trigger condition: sensor resistance <200 kΩ. Operating temperature: −40 °C to +85 °C.
- Packing: Each plastic box contains 4 film pressure sensors. Thickness ≈0.4 mm. Sensing range: 20 g–2 kg. Built on a flexible PET substrate for conformal mounting on curved or flat surfaces without loss of sensitivity. Sensors are used in series with a fixed resistor; measure the voltage across the fixed resistor: Vout = Vcc * R0 / (R0 + RS) As a rule, choose the fixed resistor R0 ≈ 1/3 to 1/2 of the sensor’s application resistance range. Selecting an appropriate fixed resistor can make pressure vs. output voltage approximately linear over a certain pressure range.
- Usage instructions: Install the sensor on a solid, flat, and smooth surface. Protect it from sharp objects. Use a cover layer (polycarbonate film or elastomer) for protection. The sensor material is not recommended for direct liquid contact and requires waterproofing if exposed. Overload will not permanently damage the sensor; it will return to normal operation after the load is removed. For designs involving motion, use soft rubber or a spring as part of the trigger mechanism.
- Pressure-threshold switch application: A typical threshold switch circuit uses a Wheatstone bridge and a voltage comparator. When pressure increases and the sensor resistance drops below R1, the comparator input U1+ exceeds U1− and the comparator output goes high. The high output can trigger downstream devices (for example, a relay to control LEDs, buzzers, motors, etc.).
Device architecture matters alongside material choice. CNTs can be dispersed as fillers in an elastomer or deposited as a network on a porous support. In either case, the substrate and microstructure influence how pressure changes the conductive paths. Consistent nanomaterial deposition is also a manufacturing concern because uneven coverage can contribute to variation in sensor performance.
Why carbon does not tell you the sensing mechanism
A carbon-based sensor is not necessarily piezoresistive. Flexible pressure sensors can use several transduction mechanisms, including:
Rank #3
- FLEXIBLE FORCE SENSITIVE SENSOR OFFERS EXTREME SPEED RESPONSE--The flexible sensor has the characteristics of flexible ultra-thin, and extreme speed response, etc
- WIDELY APPLICATIONS FOR VARIETY ITEMS' DETECTING--This Force Sensing Resistor has widely applications during daily life, such as off-bed monitoring, intelligent breathing belt, sleep monitoring, electronic shelf
- WATER-PROOF AND PRESSURE SENSITIVE SENSOR--Waterproof and pressure sensitive function
- DESIGNED WITH HIGHLY SENSITIVE NANO-METER MATERIAL REACHES HIGHLY SENSITIVE DETECTION--Highly sensitive flexible nano-meter materials can realize highly sensitive detection of pressure
- GOOD DURABILITY AND HIGH EFFICIENCY FLEX/BEND SENSOR--High sensitivity and long service life
- Piezoresistive: pressure changes resistance, often by changing contacts or pathways in a conductive network.
- Capacitive: pressure changes capacitance, for example by changing the spacing or geometry of electrodes.
- Piezoelectric or triboelectric: deformation produces an electrical response through a different physical effect.
One example of why the distinction matters is a 2020 ACS study of a porous Ecoflex–multiwalled CNT composite used in a capacitive pressure sensor. The carbon nanotubes are part of the device, but the reported sensing mechanism is capacitive rather than a resistance change. Read the ACS paper.
Independent reader supportYour contribution helps us test, update, and keep practical guides available for everyone.How to compare flexible pressure sensors
Start with the pressure range the sensor is meant to measure. A sensitivity value by itself does not show whether a device is suitable for a particular application: sensitivity can vary across a device’s working range, and a high value over a narrow interval is not automatically better for pressures outside it.
Rank #4
- Trigger force: less than 20g, trigger when the default resistance value is less than 200kΩ; Pressure sensing range: 20g ~ 10kg or more
- Pressure mode of action: static or dynamic (frequency within 10Hz); Resistance when not triggered: greater than 10MΩ
- Activation time: less than 0.01S; Operating temperature:-40 ℃ ~ 85 ℃; Durability: more than 1 million times
- Static/dynamic pressure sensing, fast response speed, long durability life
- In-bed off-bed monitoring, sleep state monitoring, intelligent running shoes: record the intensity and frequency of pressure, intelligent switch: set the force identification to prevent misoperation, counter: record the number of times of pressure
- Working range: the pressure interval over which the device is characterized.
- Sensitivity: how much the output changes with pressure; check the reported interval and measurement method.
- Hysteresis: whether the output differs as pressure increases versus decreases.
- Stability: whether the response remains consistent over time or repeated use.
- Response and recovery time: how quickly the sensor reacts to loading and returns after pressure is removed.
- Mechanism and structure: whether the sensor is piezoresistive, capacitive, piezoelectric, or triboelectric, and whether it uses a porous support, an elastomer composite, or another architecture.
- Use pattern: whether the intended measurement is static pressure, changing pressure, or both.
As a specific example—not a general benchmark—the 2020 ACS paper reports sensitivities of 6.42 kPa⁻¹ over 0–2 kPa and 1.72 kPa⁻¹ over 2–10 kPa for its porous Ecoflex–multiwalled CNT capacitive sensor. The two values describe different pressure intervals in that particular device, not flexible pressure sensors as a category. The paper reports the device and its measurements.
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Best Value
- Specifications: Package contains 2pcs RP-L-110 force pressure sensors. When resistance type sensor is not triggered, its resistance is greater than 10MΩ, and it can sense force from 20g to 10kg and above. And it can sense weak dynamic or static force
- Fast Response: Resistive pressure sensor's activation time is less than 0.01s, response time is less than 10ms, and flexible film pressure sensor triggers when default resistance value is less than 200kΩ. It works quickly to provide with timely data
- Flexible Film: The top of resistance type position sensor is flexible film, and middle is pressure-sensitive layer with 0.35mm thickness. Resistive film pressure sensor is thin and flexible to fit your device. You can use it easily in tight spaces
- Widely Applicable: Thin film pressure sensor can be used as a practical tool for your smart running shoes to record pressure intensity and frequency. Bend sensor can also be applied to out-of-bed monitoring, smart breathing belts, sleep monitoring, electronic shelves and other projects
- Stable Function: Film force sensor has a stable structure and long service life. Whether force sensing resistor is a smart switch frequently used in daily life or a smart system for automated operations, it can provide long-term stable support
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