# A Novel Method for Technology Roadmapping: Nanorobots
## 3 Results and Discussion
### Multi-Source Theme Identification and Association
\begin{table}
\begin{tabular}{c c c} \hline \hline
**Number** & **Theme** & **Phrases** \\ \hline \multirow{2}{*}{1} & Flexible pressure sensor technology & Flexible tactile sensor; CNT-based nanodevice; flexible strain; mechanical properties; nano-CW NR matrix \\ \hline \multirow{2}{*}{2} & \multirow{2}{*}{DNA molecule recognition} & Molecular machine; DNA polymers; DNA computing device; DNA nanotechnology development; DNA surface \\ \hline \multirow{2}{*}{3} & \multirow{2}{*}{Precision imaging} & Scanning electron microscopy; transmission microscopy; scanning electron; universal testing machine; electron system \\ \hline \multirow{2}{*}{4} & \multirow{2}{*}{Nanostructure design} & Nanostructure; nanotechnology; performance DT RF model; nanoscale engineering; nanomaterial assembly \\ \hline \multirow{2}{*}{5} & \multirow{2}{*}{Nanomachine processing} & Nano-surface treatment; nanoprocessing technology; molecular self-assembly; nano-sensors; nanodevices \\ \hline \multirow{2}{*}{6} & \multirow{2}{*}{Pollution control} & Pollution monitoring; risk assessment; bioaccumulation of nanomaterials; ecological impact; nanoparticle regulation \\ \hline \multirow{2}{*}{7} & \multirow{2}{*}{Drug release} & Gradual release; drug release pattern; nanomaterial release properties; microenvironment responsiveness; enhanced permeability and retention (EPR) effect \\ \hline \multirow{2}{*}{8} & \multirow{2}{*}{Composite preparation} & Dispersion performance; synthesis process; nano-coating materials; interface shear; interface modification \\ \hline \multirow{2}{*}{9} & \multirow{2}{*}{Treatment monitoring} & Nanodrug monitoring; nanoparticle tracking; dynamic observation; nanodrug distribution investigation; real-time monitoring \\ \hline \hline \end{tabular}
\end{table} 
Table 2: Clustered themes and corresponding top 5 phrases. Moreover, themes such as \"pollution control\" and \"drug release\" underscore the potential of nanorobotics in environmental protection and precision medicine. Subsequently, this section methodically sets forth the establishment of theme associations within discrete layers. Initially, technical feature vectors, which are aligned with specific themes, are derived for each time interval. The next step involves computing the average cosine similarity across all the technical feature vectors for each theme within the given time intervals. Thereafter, a critical part of the analysis is defining a similarity threshold, which is pivotal for associating themes, both within the same interval and across various intervals. The task of selecting an appropriate cosine similarity threshold is of paramount importance in theme association. This research aimed to calibrate the threshold at the maximum feasible level that still permits a valid association analysis. This careful calibration is intended to minimize the introduction of extraneous variables and to accentuate the authentic developmental patterns that emerge from the theme evolution analysis. Upon the computation of cosine similarity for themes across consecutive time intervals, a collection of 405 cosine similarity measures were generated. These measures were arrayed in descending order, from which the uppermost 60 values were chosen for establishing associations, based on the presupposition that themes within identical time intervals are inherently associated. The experimental results yielded a collection of 60 associations between themes. Within this collection, 45 associations were found to be between identical themes, which suggests a persistent or strengthening presence of these themes over the analyzed time periods. The remaining 15 associations were identified amongst distinct themes, suggesting an evolutionary trajectory or convergence between different thematic areas within the time frame analyzed. To validate our method qualitatively, \"flexible pressure sensor technology\" as a topic was searched in the Web of Science core collection, showing 1823 science publications from 2023 to 2024.