# TF Mk.1 Muscle

**Pronunciation:** *Ther-moh-fleks mark one muscle*

Also visit our [getting started guide](https://delta-robotics.gitbook.io/docs/tutorials/thermoflex-tm/getting-started-with-our-evaluation-kit) to see what's possible with the ThermoFlex™ kit and accompanying [Python API](https://delta-robotics.gitbook.io/docs/software/thermoflex-tm-python-api).

<figure><img src="https://1078621213-files.gitbook.io/~/files/v0/b/gitbook-x-prod.appspot.com/o/spaces%2Fm2yg571oTEEeXffjpREo%2Fuploads%2FDIspELQXwPLTWsib1oas%2F2025-02-15%2015.12_edited.png?alt=media&#x26;token=ca5519cc-1eaf-4133-8976-60d0ce2a0e97" alt="" width="375"><figcaption></figcaption></figure>

### Specifications

<table><thead><tr><th>Parameter</th><th width="249">Minimum</th><th>Maximum</th></tr></thead><tbody><tr><td>Nominal voltage</td><td>3 V</td><td>25 V</td></tr><tr><td>Resistance</td><td>235 mOhms (Af)</td><td>250 mOhms (Mf)</td></tr><tr><td>Instantaneous Current</td><td>(Dependent on PWM %)</td><td>106 A (2s contraction)</td></tr><tr><td>Pull Force</td><td>5 lbs (Extension return force)</td><td>25 lbs</td></tr><tr><td>Contraction Time</td><td>-</td><td>2s @ 25 V</td></tr></tbody></table>

Question about specific values? Ask Kevin: <kevin@deltaroboticsinc.com>

### Contraction Test Results

**Setup:** A variable power supply set to 15 A and an oscilloscope to track the following values.

**Load**: None

**Set Current:** 15 A

**Time to Contract (TTC)**: 35.311 s

**Total Power Consumption**: 1923 J (\~0.5 Wh)

<figure><img src="https://1078621213-files.gitbook.io/~/files/v0/b/gitbook-x-prod.appspot.com/o/spaces%2Fm2yg571oTEEeXffjpREo%2Fuploads%2FOXaN21k48ey3kKpDYX5U%2Fimage.png?alt=media&#x26;token=9ca06bac-71c2-4a11-9d7d-3ea5211a117b" alt=""><figcaption><p>What this means: The graph shows the total power consumption for a full actuation completed over 35 seconds. Standard actuations with the ThermoFlex Node Controller are under 2 seconds.</p></figcaption></figure>