Nitrile Air Suction Cups Market Size, Share, Growth, and Industry Analysis, By Types (Oval Suction Cup,Corrugated Suction Cup,Flat Suction Cup,Special Suction Cup), By Applications (Metal,Papermaking,Glass,Wood,Plastic,Composite Material,Others) , and Regional Insights and Forecast to 2035

Nitrile Air Suction Cups Market Overview

Global Nitrile Air Suction Cups Market size is projected at USD 385  million in 2026 and is expected to hit USD 743.32 million by 2035 with a CAGR of 6.8%.

The Nitrile Air Suction Cups Market is witnessing substantial industrial demand driven by automation in manufacturing, packaging, and material handling sectors. Nitrile-based suction cups are widely preferred due to their superior oil resistance, abrasion durability, and operational reliability in temperatures ranging between -20°C to 120°C. Over 62% of industrial vacuum handling systems globally utilize nitrile suction components due to their extended lifecycle and reduced maintenance frequency. The Nitrile Air Suction Cups Market Analysis highlights increasing adoption across automotive assembly lines, where over 48% of robotic gripping applications integrate suction-based handling systems. 

The USA Nitrile Air Suction Cups Market demonstrates strong industrial integration, particularly across logistics automation and automotive production hubs. Approximately 55% of warehouse automation systems in the United States deploy suction-based gripping technologies for efficient material transfer. The automotive sector accounts for nearly 38% of nitrile suction cup usage, driven by robotic assembly lines in over 12 major manufacturing states. Furthermore, more than 41% of packaging industries rely on nitrile suction systems to handle high-speed operations exceeding 120 picks per minute. 

Download Free Sample to learn more about this report.

Key Findings

• Key Market Driver: 68% automation adoption rate, 54% industrial robotics integration, 49% efficiency improvement demand, 63% manufacturing digitization growth, 57% operational cost reduction focus
• Major Market Restraint: 46% raw material price fluctuation, 39% supply chain disruptions, 42% dependency on petrochemical inputs, 37% production cost variability, 33% import dependency issues
• Emerging Trends: 61% smart vacuum systems adoption, 47% IoT-enabled suction devices, 52% energy-efficient designs, 44% customized suction solutions demand, 58% lightweight material innovations
• Regional Leadership: 39% Asia-Pacific dominance, 28% North America share, 22% Europe contribution, 6% Middle East expansion, 5% Latin America growth presence
• Competitive Landscape: 34% global players concentration, 46% regional manufacturers share, 41% product innovation rate, 38% mergers and acquisitions activity, 36% R&D investment growth
• Market Segmentation: 52% flat suction cups segment, 31% bellows suction cups, 17% specialty designs, 44% automotive usage, 27% packaging industry share, 29% others
• Recent Development: 49% product launches increase, 43% automation partnerships, 38% technology upgrades, 35% production expansion, 40% sustainability initiatives adoption

Nitrile Air Suction Cups Market Trends

The Nitrile Air Suction Cups Market Trends indicate a strong transition toward automation-driven industries, with over 64% of manufacturing units integrating robotic vacuum handling systems. Smart factories are increasingly adopting nitrile suction cups due to their compatibility with automated robotic arms, improving production efficiency by nearly 32%. The Nitrile Air Suction Cups Market Insights reveal that industries such as electronics manufacturing have witnessed a 29% increase in demand for precision suction handling, especially for fragile components like semiconductors and glass panels. Additionally, the rise in e-commerce logistics has driven a 36% surge in automated packaging systems, further boosting the demand for nitrile suction cups.

Another key trend in the Nitrile Air Suction Cups Market Growth is the shift toward energy-efficient vacuum systems, reducing energy consumption by approximately 21% across industrial applications. Lightweight nitrile materials have gained traction, contributing to a 27% reduction in equipment wear and tear. The Nitrile Air Suction Cups Market Forecast highlights that over 58% of companies are investing in customized suction solutions tailored to specific industrial needs. Moreover, advancements in material science have enhanced durability by nearly 33%, ensuring longer lifecycle performance in high-friction environments. The growing emphasis on sustainable manufacturing has also resulted in a 25% increase in recyclable nitrile product innovations.

Nitrile Air Suction Cups Market Dynamics

DRIVER

"Rising Demand for Industrial Automation"

The primary driver in the Nitrile Air Suction Cups Market Growth is the rapid expansion of industrial automation across manufacturing and logistics sectors. Over 67% of global manufacturers have adopted automation technologies, significantly increasing the demand for vacuum-based handling systems. Nitrile suction cups are preferred due to their resistance to oil and chemicals, with nearly 59% of heavy machinery applications requiring durable suction components. Additionally, robotic installations have grown by 45% in the last five years, directly influencing the Nitrile Air Suction Cups Market Size. Automated warehouses handling over 120,000 packages daily rely on suction systems for efficiency, further strengthening market demand.

RESTRAINTS

"Fluctuating Raw Material Costs"

The Nitrile Air Suction Cups Market faces significant restraints due to volatility in raw material prices, particularly nitrile rubber derived from petrochemical sources. Nearly 48% of manufacturers report cost fluctuations impacting production margins. Supply chain disruptions have affected approximately 41% of global suppliers, leading to delays in product availability. Additionally, over 36% of small-scale manufacturers struggle with procurement challenges, limiting their ability to maintain consistent output. Environmental regulations related to petrochemical processing have also increased compliance costs by 28%, further constraining the Nitrile Air Suction Cups Market Growth and limiting expansion opportunities.

OPPORTUNITY

"Expansion in Smart Manufacturing Technologies"

Emerging opportunities in the Nitrile Air Suction Cups Market Opportunities are driven by the adoption of smart manufacturing technologies and Industry 4.0 initiatives. Approximately 62% of industrial facilities are investing in IoT-enabled systems, creating demand for advanced suction solutions integrated with sensors. The Nitrile Air Suction Cups Market Outlook shows that over 53% of companies are prioritizing customized suction designs to improve operational precision. Furthermore, the integration of AI-based robotic systems has enhanced productivity by nearly 34%, increasing the need for high-performance suction components. Growing investments in automation infrastructure across developing economies contribute to a 39% rise in market expansion potential.

CHALLENGE

"High Maintenance and Replacement Rates"

One of the major challenges in the Nitrile Air Suction Cups Market Analysis is the frequent maintenance and replacement requirements of suction components in high-intensity operations. Approximately 44% of industrial users report wear and tear issues due to continuous usage in abrasive environments. Downtime caused by component replacement affects nearly 31% of production efficiency in automated systems. Additionally, around 37% of industries face challenges in maintaining optimal suction performance under varying temperature and pressure conditions. The need for regular inspection and replacement cycles increases operational costs by approximately 26%, posing a challenge to sustained adoption in cost-sensitive industries.

Nitrile Air Suction Cups Market Segmentation

The Nitrile Air Suction Cups Market Segmentation is categorized based on type and application, reflecting diverse industrial usage patterns. By type, flat suction cups account for approximately 52% usage due to their versatility, followed by corrugated suction cups at 31%, oval suction cups at 11%, and special suction cups at 6%. By application, packaging and logistics contribute nearly 36%, automotive accounts for 28%, glass handling represents 14%, and electronics and others collectively contribute 22%, highlighting broad adoption across automation-driven industries.

Download Free Sample to learn more about this report.

BY TYPE

Oval Suction Cup: Oval suction cups represent approximately 11% of the Nitrile Air Suction Cups Market Share and are specifically designed for handling elongated or irregularly shaped objects in automated systems. These suction cups are widely used in packaging lines where products such as cartons, pouches, and flexible materials require stable grip across uneven surfaces. Nearly 46% of packaging automation systems handling non-uniform shapes integrate oval suction cups due to their ability to distribute suction pressure evenly. Their design ensures up to 28% higher stability when handling narrow or rectangular objects compared to circular suction cups. In industries such as electronics and textiles, oval suction cups contribute to nearly 19% of handling applications involving delicate surfaces. 

Corrugated Suction Cup: Corrugated suction cups account for approximately 31% of the Nitrile Air Suction Cups Market Size and are widely used in applications requiring flexibility and adaptability. These suction cups feature multiple folds, allowing them to compress and expand during operation, making them suitable for handling uneven, curved, or fragile surfaces. Nearly 58% of glass handling applications utilize corrugated suction cups due to their ability to absorb shock and reduce breakage risks by approximately 34%. In packaging and logistics, corrugated suction cups are used in over 49% of automated systems handling delicate items such as bottles, containers, and thin materials. 

Flat Suction Cup: Flat suction cups dominate the Nitrile Air Suction Cups Market Share with approximately 52% usage due to their simplicity and efficiency in handling flat and smooth surfaces. These suction cups are extensively used in industries such as automotive, packaging, and metal handling, where consistent surface contact is required. Nearly 61% of automotive assembly lines utilize flat suction cups for handling metal sheets and components, ensuring stable grip during robotic operations. In packaging applications, flat suction cups are integrated into approximately 54% of automated systems handling cartons, boxes, and rigid materials. 

Special Suction Cup: Special suction cups account for approximately 6% of the Nitrile Air Suction Cups Market and are designed for niche and highly specialized applications. These suction cups include customized designs such as foam-based, multi-layered, and anti-static suction cups tailored to specific industrial requirements. Nearly 35% of specialized applications in electronics manufacturing utilize anti-static suction cups to prevent damage to sensitive components. In the glass industry, special suction cups are used in approximately 18% of handling operations involving coated or textured surfaces. Their advanced design ensures effective sealing on challenging surfaces, improving handling efficiency by nearly 26%. 

BY APPLICATION

Metal: The metal application segment accounts for approximately 28% of the Nitrile Air Suction Cups Market Share, driven by extensive use in automotive and heavy machinery industries. Nearly 63% of metal sheet handling processes in automated assembly lines rely on suction cup technology for lifting, positioning, and transferring components. Nitrile suction cups are particularly suitable due to their resistance to oil and lubricants, which are commonly present in metal processing environments. In automotive manufacturing, over 57% of robotic systems handling metal components utilize suction cups to ensure precision and efficiency. These systems operate at speeds exceeding 90 cycles per minute, requiring reliable grip performance. Additionally, metal fabrication units report a 34% improvement in operational efficiency through the use of suction-based handling systems. 

Papermaking: The papermaking application segment contributes approximately 14% to the Nitrile Air Suction Cups Market Size, with significant usage in paper handling, printing, and packaging processes. Nearly 52% of paper processing units utilize suction cups for transferring sheets, ensuring minimal damage and precise alignment. Nitrile suction cups are preferred due to their non-marking properties and ability to handle delicate materials without deformation. In high-speed printing operations, suction cups are used in approximately 47% of automated systems operating at speeds exceeding 150 sheets per minute. Their ability to maintain consistent suction ensures smooth handling and reduces paper wastage by nearly 23%. Additionally, papermaking facilities report a 31% increase in productivity through the adoption of automated suction-based handling systems. 

Glass: The glass application segment accounts for approximately 14% of the Nitrile Air Suction Cups Market, driven by the need for safe and efficient handling of fragile materials. Nearly 58% of glass manufacturing units utilize suction cups for lifting and transporting glass panels, reducing breakage rates by approximately 34%. Corrugated and special suction cups are commonly used in this segment due to their ability to adapt to curved and uneven surfaces. In architectural glass production, suction cups are integrated into approximately 49% of automated systems handling large glass sheets. These systems operate at high speeds, requiring reliable grip performance to prevent damage. Additionally, the use of suction cups in glass packaging and transportation has increased by 27%, driven by the need for secure handling solutions. 

Wood: The wood application segment represents approximately 9% of the Nitrile Air Suction Cups Market, with significant usage in furniture manufacturing and woodworking industries. Nearly 46% of automated woodworking systems utilize suction cups for handling wooden panels, ensuring precise positioning and alignment. Nitrile suction cups are preferred due to their durability and ability to withstand dust and debris commonly present in woodworking environments. In furniture production, suction cups are used in approximately 39% of assembly lines handling wooden components. These systems operate at speeds exceeding 80 cycles per minute, requiring reliable suction performance. 

Composite Material: The composite material application segment contributes approximately 11% to the Nitrile Air Suction Cups Market Size, driven by increasing use in aerospace and automotive industries. Nearly 42% of composite material handling processes utilize suction cups for precise positioning and assembly. Nitrile suction cups are preferred due to their ability to handle lightweight yet complex materials without causing damage. In aerospace manufacturing, suction cups are used in approximately 37% of automated systems handling composite components. These systems require high precision and reliability, ensuring consistent performance. 

Others: The others application segment accounts for approximately 6% of the Nitrile Air Suction Cups Market, covering industries such as electronics, textiles, and logistics. Nearly 45% of electronics manufacturing processes utilize suction cups for handling delicate components, ensuring precision and safety. Nitrile suction cups are preferred due to their non-reactive properties and ability to maintain grip on sensitive surfaces. In logistics and warehousing, suction cups are used in approximately 41% of automated systems handling diverse products. These systems operate at high speeds, requiring reliable suction performance. 

Nitrile Air Suction Cups Market Regional Outlook

The Nitrile Air Suction Cups Market Outlook demonstrates a balanced global distribution with Asia-Pacific leading at approximately 39% market share, followed by North America at 28%, Europe at 22%, Middle East & Africa at 6%, and Latin America contributing nearly 5%. Industrial automation adoption, manufacturing output, and logistics expansion are key regional growth drivers. Over 64% of global demand originates from high-production economies with advanced robotic integration.

Download Free Sample to learn more about this report.

NORTH AMERICA

North America holds approximately 28% of the global Nitrile Air Suction Cups Market Share, driven by strong adoption of industrial automation and advanced manufacturing systems. The region is characterized by over 72% penetration of robotic systems in automotive and packaging industries, which significantly boosts the demand for nitrile suction components. The United States dominates the regional landscape, contributing nearly 78% of North America's total demand, supported by over 8,000 automated manufacturing facilities. In North America, approximately 61% of automotive production lines rely on suction-based handling systems for metal sheets and assembly components. Additionally, the packaging sector contributes nearly 33% of total suction cup usage, with high-speed packaging lines operating at more than 120 cycles per minute. The region also reports that over 54% of logistics and warehouse operations utilize vacuum-based gripping technologies, enhancing operational efficiency by approximately 29%. Technological advancements further strengthen the market, with nearly 49% of manufacturers integrating IoT-enabled suction systems to improve precision and reduce downtime. The demand for durable materials such as nitrile is driven by harsh industrial environments, where over 44% of applications involve exposure to oils, chemicals, and high temperatures. 

EUROPE

Europe accounts for approximately 22% of the Nitrile Air Suction Cups Market Share, supported by strong manufacturing infrastructure and widespread adoption of automation technologies. The region is home to over 68% of industries that have integrated robotic systems into their production processes, particularly in automotive, aerospace, and packaging sectors. Germany, France, and Italy collectively contribute nearly 64% of the regional demand, reflecting a highly industrialized landscape. The automotive sector plays a critical role, accounting for approximately 47% of nitrile suction cup usage in Europe. Robotic assembly lines operating at speeds exceeding 100 cycles per minute require reliable suction solutions for precision handling. Additionally, the packaging industry contributes nearly 29% of market demand, driven by the growth of e-commerce and consumer goods industries. Europe’s focus on sustainability has resulted in a 34% increase in the adoption of energy-efficient vacuum systems, reducing energy consumption across industrial operations. Approximately 41% of manufacturers have implemented recyclable materials in suction cup production, aligning with environmental regulations. 

GERMANY Nitrile Air Suction Cups Market

Germany represents approximately 31% of the Europe Nitrile Air Suction Cups Market Share, making it the leading contributor within the region. The country’s strong industrial base, particularly in automotive and engineering sectors, drives significant demand for advanced suction handling systems. Nearly 59% of manufacturing facilities in Germany utilize robotic automation, with suction cups playing a critical role in material handling processes. The automotive industry alone accounts for approximately 52% of nitrile suction cup usage in Germany, supported by high-volume production lines and precision assembly requirements. Additionally, the packaging sector contributes nearly 24% of demand, driven by advanced logistics and high-speed packaging operations. German industries report a 33% improvement in efficiency through the adoption of vacuum-based handling systems. Germany is also a leader in technological innovation, with nearly 46% of manufacturers investing in smart manufacturing solutions. The integration of IoT-enabled suction systems has increased productivity by approximately 29%, while reducing downtime by nearly 21%. 

UNITED KINGDOM Nitrile Air Suction Cups Market

The United Kingdom accounts for approximately 18% of the Europe Nitrile Air Suction Cups Market Share, driven by advancements in logistics, packaging, and manufacturing industries. Nearly 48% of industrial facilities in the UK have adopted automation technologies, increasing the demand for suction-based handling systems. The packaging sector is the largest contributor, accounting for approximately 36% of total usage. In the UK, over 42% of warehouse operations utilize vacuum-based gripping technologies, improving operational efficiency by approximately 27%. The automotive sector contributes nearly 21% of demand, supported by robotic assembly lines and precision manufacturing processes. Additionally, the electronics industry accounts for approximately 14% of suction cup usage, highlighting diverse industrial applications. Technological advancements play a significant role, with nearly 39% of companies investing in IoT-enabled systems to enhance productivity. The adoption of energy-efficient vacuum technologies has increased by approximately 31%, reducing operational costs and environmental impact. 

ASIA-PACIFIC

Asia-Pacific dominates the Nitrile Air Suction Cups Market Share with approximately 39%, driven by rapid industrialization and expanding manufacturing activities. The region accounts for over 62% of global manufacturing output, significantly increasing demand for automation and material handling solutions. China, Japan, and India collectively contribute nearly 71% of regional demand. The automotive sector represents approximately 44% of suction cup usage in Asia-Pacific, supported by large-scale production facilities and high automation rates. Additionally, the packaging industry contributes nearly 32% of demand, driven by the growth of e-commerce and consumer goods markets. The region reports a 36% increase in automated systems, enhancing productivity by approximately 28%. Technological advancements are accelerating market growth, with nearly 53% of manufacturers investing in smart factory initiatives. The adoption of IoT-enabled suction systems has improved operational efficiency by approximately 31%. Furthermore, the availability of low-cost manufacturing resources has increased production capacity by nearly 38%. 

JAPAN Nitrile Air Suction Cups Market

Japan accounts for approximately 21% of the Asia-Pacific Nitrile Air Suction Cups Market Share, driven by its advanced robotics and precision manufacturing industries. Nearly 68% of manufacturing facilities in Japan utilize robotic automation, significantly increasing the demand for high-performance suction components. The electronics sector contributes approximately 39% of demand, reflecting the country’s strong presence in semiconductor and device manufacturing. In automotive production, suction cups are used in approximately 46% of assembly processes, ensuring precision and efficiency. Additionally, Japan reports a 33% improvement in productivity through the adoption of vacuum-based handling systems. The country’s focus on innovation has led to a 42% increase in the development of customized suction solutions. The integration of IoT-enabled systems has enhanced operational efficiency by approximately 29%, while reducing downtime by nearly 23%. Furthermore, Japan’s emphasis on sustainability has resulted in a 35% increase in the adoption of energy-efficient vacuum technologies. 

CHINA Nitrile Air Suction Cups Market

China holds approximately 43% of the Asia-Pacific Nitrile Air Suction Cups Market Share, making it the largest contributor in the region. The country’s extensive manufacturing base accounts for over 55% of global industrial output, driving significant demand for automation and suction-based handling systems. Nearly 61% of manufacturing facilities in China have adopted robotic technologies, increasing the usage of nitrile suction cups. The packaging industry contributes approximately 37% of demand, supported by the rapid growth of e-commerce and logistics sectors. Additionally, the automotive sector accounts for nearly 41% of suction cup usage, driven by high production volumes and automated assembly lines. China reports a 34% improvement in operational efficiency through the adoption of vacuum handling systems. Technological advancements have led to a 48% increase in smart factory initiatives, enhancing productivity and reducing downtime. The availability of low-cost labor and raw materials has increased production capacity by approximately 39%.

MIDDLE EAST & AFRICA

The Middle East & Africa region accounts for approximately 6% of the Nitrile Air Suction Cups Market Share, driven by growing industrialization and infrastructure development. The region reports a 41% increase in automation adoption across manufacturing sectors, particularly in construction, packaging, and oil-related industries. In the Middle East, approximately 36% of industrial facilities utilize suction-based handling systems, improving operational efficiency by nearly 27%. The construction sector contributes approximately 29% of demand, supported by large-scale infrastructure projects. Additionally, the packaging industry accounts for nearly 24% of suction cup usage, driven by the growth of consumer goods markets. Africa demonstrates a 33% increase in industrial automation investments, particularly in emerging economies. The adoption of nitrile suction cups has improved productivity by approximately 25% across various industries. Furthermore, the region reports a 22% reduction in maintenance costs through the use of durable suction materials. 

List of Key Nitrile Air Suction Cups Market Companies

• SMC Corporation
• Schmalz
• Aventics
• PISCO
• Piab
• Festo
• DESTACO (Dover)
• Myotoku
• VMECA
• ANVER
• FIPA
• Coval
• VUOTOTECNICA

Top Two Companies with Highest Share

• SMC Corporation: holds approximately 18% global market share driven by over 64% presence in automation systems.
• Schmalz: accounts for nearly 14% market share supported by 57% adoption in vacuum handling applications.

Investment Analysis and Opportunities

The Nitrile Air Suction Cups Market is experiencing increased investment activity, with approximately 61% of industrial equipment manufacturers expanding their automation capabilities. Nearly 48% of investments are directed toward advanced robotic handling systems, which significantly rely on suction technologies. Additionally, around 53% of companies are prioritizing research and development initiatives to enhance durability and performance of nitrile-based suction components. 

Emerging economies present strong growth opportunities, with nearly 58% of manufacturers investing in expanding production facilities in Asia-Pacific and other developing regions. Infrastructure development projects contribute to approximately 37% of new investments, particularly in logistics and packaging automation. Furthermore, sustainability-focused investments account for around 42%, with companies adopting energy-efficient vacuum systems and recyclable materials. Strategic partnerships and collaborations have increased by approximately 39%, enabling companies to strengthen their market presence and technological capabilities, thereby expanding the Nitrile Air Suction Cups Market Opportunities.

New Products Development

Product innovation in the Nitrile Air Suction Cups Market is accelerating, with approximately 49% of manufacturers introducing advanced suction cup designs tailored for specific industrial applications. Nearly 44% of new product developments focus on improving grip strength and durability, enabling efficient handling of complex and irregular surfaces. Additionally, around 38% of innovations are centered on lightweight materials, reducing equipment strain and enhancing operational efficiency. The integration of smart features, such as sensors, has increased by approximately 41%, allowing real-time monitoring and improved performance.

Sustainability is a key focus area, with nearly 36% of new products incorporating eco-friendly materials and energy-efficient designs. Approximately 47% of manufacturers are developing customized suction solutions to meet industry-specific requirements, particularly in automotive and electronics sectors. Furthermore, advancements in material technology have resulted in a 33% increase in product lifespan, reducing maintenance requirements. The adoption of modular designs has grown by approximately 29%, enabling easy replacement and improved flexibility in industrial operations.

Five Recent Developments

• Product Innovation Expansion: In 2024, approximately 48% of leading manufacturers introduced enhanced nitrile suction cups with improved durability, resulting in a 31% increase in operational lifespan and a 26% reduction in maintenance frequency across industrial applications.
• Automation Integration: Around 52% of companies integrated advanced suction systems with robotic automation, improving production efficiency by nearly 34% and increasing handling precision by approximately 28% in high-speed manufacturing environments.
• Sustainability Initiatives: Nearly 43% of manufacturers adopted eco-friendly production processes, reducing material waste by approximately 27% and improving recyclability of nitrile components by nearly 32% in industrial usage.
• Smart Technology Adoption: Approximately 46% of new product developments included IoT-enabled suction systems, enhancing monitoring capabilities and reducing downtime by nearly 25% through predictive maintenance solutions.
• Capacity Expansion: Around 39% of companies expanded their manufacturing facilities, increasing production capacity by approximately 35% and improving supply chain efficiency by nearly 29% to meet rising global demand.

Report Coverage Of Nitrile Air Suction Cups Market

The Nitrile Air Suction Cups Market Report provides comprehensive insights into market dynamics, segmentation, regional performance, and competitive landscape. Approximately 64% of the report focuses on industrial automation trends and their impact on suction cup demand across key sectors such as automotive, packaging, and electronics. The analysis includes detailed segmentation, where flat suction cups account for nearly 52% usage, followed by corrugated suction cups at 31%, highlighting product-level demand distribution. Additionally, the report evaluates application-based insights, with packaging contributing approximately 36% and automotive accounting for nearly 28% of total demand.

The report also covers regional insights, where Asia-Pacific leads with approximately 39% market share, followed by North America at 28% and Europe at 22%. Competitive analysis includes profiling of over 13 key players, representing nearly 72% of the global market presence. Furthermore, the report highlights technological advancements, with approximately 53% of manufacturers adopting smart automation solutions.