Enabling mechanically adaptive 4D printing with cellulose nanocrystals
Bibliographic record
Abstract
Additive manufacturing of stimulus-responsive materials is an area of four-dimensional (4D) printing that is continuing to gain interest. Cellulose nanocrystal (CNC) thermoplastic nanocomposites have been demonstrated as a water-responsive, mechanically adaptive material that shows promise in generating 4D-printed structures. In this study, a 10 wt% CNC thermoplastic polyurethane (TPU) nanocomposite was produced through a masterbatching process and printed using fused filament fabrication. A design of experiments was implemented to establish a processing window to highlight the effects of thermal energy input on the mechanical adaptivity of the printed parts. The combination of high temperatures and low speeds resulted in thermal energies that induced degradation of the CNC/TPU network and reduced the absolute values of storage moduli, but the mechanical adaptation persisted for all the printed samples. However, for slower speeds and increasing temperatures, the nanocomposites experienced a 15% decrease in adaptability. Further, a folded box structure was printed to establish the reversibility of the mechanical response and corresponding ability to generate a structure that can serve as a deployable shape-memory material based on response to water. The printed structure demonstrated fixity and recovery values of 76 and 42%, respectively. These results show significant promise for CNC/TPU nanocomposites in 4D-printed adaptable structures for academic and industrial applications.
Fetched live from OpenAlex and de-inverted. Abstracts are not stored in this database: the inverted indexes are 8.6 GB of the frame’s 9.3 GB of text, and the host has 13 GB free.
How this classification was reachedexpand
Full frame machine prediction
Teacher imitationNot calibrated prevalence, not ground truth. Human validation pending. The Gemma side is a direct model label for every work in the frame, read from the title-only record. The Codex side is a classifier learned from the 10,348 direct Codex labels and calibrated to design-weighted sample rates; fields without enough sample support carry no Codex call. Candidate is the union of the two sides; consensus is their intersection. These outputs are machine_predicted_unvalidated and are not human labels.
Distilled classifier scores by category (both heads)
| Category | Codex | Gemma |
|---|---|---|
| Metaresearch | 0.000 | 0.000 |
| Meta-epidemiology (narrow) | 0.000 | 0.000 |
| Meta-epidemiology (broad) | 0.000 | 0.000 |
| Bibliometrics | 0.000 | 0.000 |
| Science and technology studies | 0.000 | 0.000 |
| Scholarly communication | 0.000 | 0.000 |
| Open science | 0.000 | 0.000 |
| Research integrity | 0.000 | 0.000 |
| Insufficient payload (model declined to judge) | 0.001 | 0.000 |
Machine scores (provisional)
The two teacher heads of the student model, read on this work. A score orders the frame for review; it never asserts a category, and the validation status ships verbatim with every row.
Baseline scores from an immature model (maturity gate not passed, 7 training rounds). Scores rank; they never assert a category.
score_only:v0-immature-baseline · verbatim from the scoring run: score_only means the number may rank works, and no category label ships from itClassification
machine, unvalidatedMachine predicted; a candidate call from one source (direct Gemma or distilled Codex), not a consensus.
How this classification was reached, model by model and score by score, is at the end of the page under "How this classification was reached".