Two Decades of Internet of Things Scholarship: A Thematic Synthesis of Research Trends, Gaps, and Publication Patterns

Internet of Things, systematic review, thematic synthesis, research gaps, bibliometric analysis, edge computing, artificial intelligence integration.

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June 13, 2026

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The Internet of Things (IoT) has evolved over nearly two decades from a niche concept centered on radio-frequency identification into a pervasive technological substrate spanning healthcare, manufacturing, transportation, energy, and consumer environments. Despite accelerating publication volume, the field's literature has not been systematically synthesized across this two-decade horizon to identify thematic evolution, gap patterns, and structural features of publishing. This study addresses that need through a quantitative thematic synthesis of 235 IoT studies published between 2009 and 2026. Using a controlled vocabulary applied to study keywords, key findings, and identified gaps, the corpus was coded across 18 themes, 10 finding-type categories, and 12 gap categories, with cross-tabulations against publication era, indexing platform, and authorship configuration. Three findings stand out. First, architecture and framework proposals (45.5%) and security and privacy (35.7%) dominate IoT scholarship, while artificial intelligence and machine learning integration has risen from absent before 2018 to 29% of 2024–2026 studies—the steepest trend in the corpus. Second, a structural tension exists between gap recognition and gap closure: 33.6% of studies flag the absence of real-world empirical validation as a gap, but only 7.7% deliver such validation. Third, the corpus is dispersed across 169 outlets with no dominant venue, and indexing tier shows only weak association with the depth of reported findings. The study concludes that the most defensible openings for future IoT research lie in long-horizon empirical validation, vendor-neutral interoperability, and governance-oriented studies.