# iMEK Vibrotactile Actuator Characterization Database — Dataset Package

Snapshot 2026-08-24 · Version 1.0 (draft for TORE deposit) · License: CC BY 4.0 (see LICENSE.txt)

Standardized idle/blocked characterization of **26 commercial vibrotactile actuators** (22 LRA, 4 ERM): frequency responses of acceleration, velocity, displacement, force and mechanical power; electrical impedance magnitude; per-voltage sweeps (LRA, 6 drive voltages × 69 frequency points); SNR sweeps (ERM); derived KPIs; photographs. Measurement methodology and KPI mathematics are documented in the accompanying Technical Notes (N1: measurement concept, N2: KPI derivation) and the dataset description note (this deposit's PDF).

## Package contents

| Path | Content |
|---|---|
| `actuator_quantification_snapshot_2026-08-24.sql` | Complete MySQL dump (schema + data), the citable primary object |
| `csv/Actuator.csv` | Catalogue: 26 rows, one per actuator (model, manufacturer, class, volume, mass, rated voltage, peak values with resonance frequencies, KPIs, provenance columns) |
| `csv/Measurement_ALL.csv` | Summary frequency responses: 1 842 rows (69 points/LRA at 23–490 Hz; 80–84 points/ERM at ~8–35 Hz) |
| `csv/PW_Bode_Amplitude_ALL.csv` | Electrical impedance magnitude (Ω): 1 842 rows, row-aligned with Measurement_ALL via `id` |
| `csv/PW_Measurement_LRA.csv` | Per-voltage sweeps, LRA only: 9 108 rows (1.0/1.4/1.8/2.2/2.6/3.0 V) |
| `csv/PW_Table.csv` | Drift and bandwidth per LRA and voltage: 132 rows (LDD, CDD, resonance bandwidth) |
| `csv/PW_SNR_ERM.csv` | SNR vs. drive voltage, ERM only: 324 rows |
| `csv/Pictures_index.csv` | Index of the photograph files (actuator_id ↔ file) |
| `pictures/actXX_picYY.png` | 16 photographs, extracted from the database blobs |

Units and column-by-column semantics: see the dataset description Technical Note (deposited PDF) — in short: frequencies in Hz, voltages in V, acceleration in g, velocity in m/s, displacement in m, force in N, mechanical power in W, impedance in Ω, SNR in dB, volume in cm³, mass in g.

## Known limitations of this release

`snr_power` is 0.0 in Measurement_ALL and PW_SNR_ERM (meaningful SNR values live in PW_Measurement_LRA and the acceleration/force SNR columns). The impedance-phase table and the ERM voltage–frequency table exist in the SQL schema but are empty. All `comment` columns are NULL. `mass_in_g` = 0 for VL32158H-L25 (metadata gap). Relational integrity is by convention (no enforced foreign keys except Pictures).

## Reuse

- **SQL:** restore with `mysql < actuator_quantification_snapshot_2026-08-24.sql` (MySQL 8) or convert to SQLite.
- **CSV:** tool-independent; `Measurement_ALL` joins `PW_Bode_Amplitude_ALL` on `id` (not on frequency).
- **MATLAB:** the `databases-interface` toolbox (connect / listActuators / getFrequencyResponse / getActuator / getSNR / getPictures) reads the live database or a restored snapshot.
- Query hints: `force` is a reserved word in MySQL 8 (use backticks); compare `input_voltage` with a tolerance (floating point).

## How to cite

Following the TORE citation format:

> Elnwegy, A.; Lüer, J.; Becker, M.; Tortorici, O.; Sadeghi, M.; Kern, T. A. (2026). iMEK Vibrotactile Actuator Characterization Database (Dataset). TUHH Universitätsbibliothek. https://doi.org/10.15480/882.18053 

Related resources are linked via DataCite relatedIdentifiers: Technical Notes N1/N2 (Is Supplement To / Is Described By), the journal publication, and the web frontend https://ligeti.ha.tuhh.de/actuators/. Future data additions appear as new TORE versions with their own DOIs ("Is New Version Of"); this snapshot remains the archival version of record (10-year retention per TORE research data licence).

## TORE submission notes (for the depositing author)

TORE presents files as a flat list without folders. Recommended upload layout: `csv.zip` (this csv/ folder), `pictures.zip` (this pictures/ folder), plus the SQL dump, `README.md`, `LICENSE.txt` and the dataset description Technical Note PDF as individual, directly downloadable files. The CSV files are the canonical open serialization (FAIR/format-migration clause); the SQL dump is the convenience form for database restoration. Metadata to prepare for the submission form: English abstract (published CC0), 5–8 keywords, DDC class 620 (Engineering), ORCID iDs of all creators, BMFTR funding reference (Grant 13IHS232C, "Innovative Hochschule") and City of Hamburg. Open questions for tore@tuhh.de are listed in `../../06_Referenzen/TORE_Regeln_Recherche.md`.

Funded by the BMFTR programme "Innovative Hochschule" (Grant No. 13IHS232C) and the City of Hamburg.