docs: LLD and liquid classes (#19806)

emilyburghardt · CaseyBatten · commit 0096f319a0a8 · 2025-11-04T09:59:21.000-05:00
# Overview reworking the "what's new on Flex" section > "Flex-exclusive features" for a few reasons: - the OT-2 and Flex comparison is no longer what's most important in the introduction. here, I've walked back the comparison text (but still include a small section to do so). - this section can be useful to us to describe what's different/exclusive to Flex without comparison. This can also be a soft landing place for new features that aren't ready for an entire section, but will be one day (like LLD. After 8.8, this could very well get its own section). -also sprinkling throughout: LLD, liquid classes, a mention of liquid classes in QT. Trying to bridge the gap before some of these features get more new shiny things added to them and can have their own section (LLD mostly).  ## Test Plan and Hands on Testing  ## Changelog  ## Review requests  ## Risk assessment
diff --git a/docs/flex/docs/introduction.md b/docs/flex/docs/introduction.md
@@ -6,25 +6,28 @@ Opentrons Flex is a liquid-handling robot designed for high throughput and compl
 
 Flex workstations come with all of the equipment — robot, hardware, and labware — that you need to get started automating common lab tasks. For other applications, Opentrons Flex runs on fully open-source software and firmware, and does not require proprietary reagents and labware, giving you control over how you design and run your protocols.
 
-## What's new in Flex
+## Flex-exclusive features
 
-Opentrons Flex is part of the Opentrons liquid handler series of robots. Users of Opentrons Flex may be familiar with the Opentrons OT-2, our personal pipetting robot. Flex goes beyond the capabilities of OT-2 in several key areas, delivering higher throughput and walkaway time.
+Opentrons Flex includes advanced features to help you automate any workflow, available only on the Flex. 
 
 | Feature | Description |
 | --- | --- |
-| **Pipette throughput** | Flex pipettes have 1, 8, or 96 channels. The 96-channel pipette operates on 12 times as many wells at once as the largest OT-2 pipette.                                                                                                                               |
-| **Pipette and tip capacities** | Flex pipettes have larger volume ranges (1–50 µL, 5–1000 µL). The 5–1000 µL Flex pipettes can work with any volume of Opentrons Flex tips. This is an improvement over OT-2 pipettes, which have smaller ranges and must use tips with a matching volume range.                         |
+| **Pipette throughput** | <ul><li>Flex pipettes have 1, 8, or 96 channels. The 96-channel pipette is available only for Flex.</li><li> Flex pipettes have large volume ranges. The 5–1000 µL pipettes work with any volume of Opentrons Flex tips, making it easy to automate a wide range of pipetting tasks in a single workflow.</li></ul> |
 | **Gripper** | The Opentrons Flex Gripper picks up and moves labware around the deck automatically, without user intervention. The gripper enables more complex workflows within a single protocol run.                                                                             |
 | **Automated calibration** | Positional calibration of Flex pipettes and the gripper is fully automated. Press one button, and the instrument will move to precision-machined points on the deck to determine its exact position, saving that data for use in your protocols.                      |
-| **Touchscreen** | Flex has its own touchscreen interface that lets you control it directly, in addition to using the Opentrons App. Use the touchscreen to start protocol runs, check job status, and change settings right on the robot.                                                 |
-| **Module caddies** | Flex modules fit into caddies that occupy space below the deck. Caddies place your labware closer to the deck surface and allow for below-deck cable routing. Caddies enable even more module and labware configurations on the deck.                                  |
-| **Deck slot coordinates** | Deck slots on Flex are numbered with a coordinate system (A1–D4) which is similar to how wells are numbered on labware.                                                                                                                                             |
-| **Movable trash** | The trash bin can go in multiple deck locations on Flex. The default location (slot A3) is the recommended position. You can also use the gripper to dispose of trash in the optional waste chute.                                                                     |
-| **Size and weight** | Flex is a bit bigger and much heavier than OT-2. Installation tasks on Flex require the assistance of a lab partner.                                                                                                                                                   |
+| **Touchscreen** | Flex has its own touchscreen interface that lets you control it directly, in addition to using the Opentrons App. Use the touchscreen to start protocol runs, perform quick transfers, check job status, and change settings right on the robot.                                                 |
+| **Module caddies** | Flex modules fit into caddies that occupy space below the deck. Caddies place your labware closer to the deck surface and allow for below-deck cable routing. Caddies enable even more module and labware configurations on the deck. |
+| **Moveable trash** | The trash bin can go in multiple deck locations on Flex. The default location (slot A3) is the recommended position. You can also use the gripper to dispose of trash in the optional waste chute. |
+| **Liquid detection** | Pressure sensors in Flex pipettes detect liquid in wells, including tip contact and liquid level. This feature lets you control the Flex's pipetting relative to a liquid meniscus, and alerts you if wells are empty. |
+| **Liquid classes** | Use [liquid class settings](https://docs.opentrons.com/v2/liquid_classes.html) to optimize Flex's pipetting behavior for your liquids, including fine-tuned control of pipette actions like flow rate and submerge speed. You can easily apply Opentrons-verified settings for aqueous, viscous, or volatile liquids using Python commands, in a quick transfer, or in Protocol Designer. |
 
-A detailed [comparison of robot technical specifications](https://opentrons.com/products/robots/) is available on the Opentrons website.
+## Flex and OT-2 
 
-Both Flex and OT-2 robots run on our open-source software, and the Opentrons App can control both types of robots at once. While OT-2 protocols can't be run directly on Flex, it's straightforward to adapt them (see the [OT-2 Protocols section][ot-2-python-protocols] of the Protocol Development chapter for details).
+Opentrons Flex is part of the Opentrons liquid handler series of robots. Flex goes beyond the capabilities of the Opentrons OT-2, our personal pipetting robot, in several key areas, delivering higher throughput and walkaway time. 
+
+Both the Opentrons Flex and OT-2 robots run on open-source software, and the Opentrons App can control both types of robots at once. In this manual, you can read more about differences in operating the Flex and its hardware. A detailed [comparison of robot technical specifications](https://opentrons.com/products/robots/) is available on the Opentrons website.
+
+While OT-2 protocols can't be run directly on Flex, it's straightforward to adapt them (see the [OT-2 Protocols section][ot-2-python-protocols] of the Protocol Development chapter for details).
 
 ## Flex workstations
 
diff --git a/docs/flex/docs/protocols/python-api.md b/docs/flex/docs/protocols/python-api.md
@@ -21,7 +21,7 @@ Python protocols generally follow the same basic structure:
 
     - Locations of [modules](https://docs.opentrons.com/v2/new_modules.html), [labware](https://docs.opentrons.com/v2/new_labware.html), and [deck fixtures](https://docs.opentrons.com/v2/deck_slots.html#deck-configuration).
 
-    - [Liquid](https://docs.opentrons.com/v2/new_labware.html#labeling-liquids-in-labware) types and locations (optional).
+    - Liquid [classes](https://docs.opentrons.com/v2/liquid_classes) or [types and locations](https://docs.opentrons.com/v2/new_labware.html#labeling-liquids-in-labware) (optional).
 
     - Commands the system will physically execute (e.g., [simple](https://docs.opentrons.com/v2/new_atomic_commands.html) or [complex](https://docs.opentrons.com/v2/new_complex_commands.html) liquid
       handling commands, [module](https://docs.opentrons.com/v2/new_modules.html) commands, or [movement](https://docs.opentrons.com/v2/robot_position.html) commands).
@@ -85,6 +85,10 @@ Starting in API version 2.22, you can move individual robot motors like the gant
 
 Unlike other protocol commands, robot motor control commands execute movements independent of labware and hardware positions on the Flex. This lets you complete advanced tasks, like using 3D-printed labware in your protocols, moving the Flex's z-axis carriage without a pipette attached, or simultaneously pipetting and holding labware with the Flex Gripper. 
 
+###  Liquid level detection 
+
+Sensors in Flex pipettes can detect the level of liquid in a well. You can use this feature to target a [liquid meniscus](https://docs.opentrons.com/v2/robot_position.html?highlight=liquid+level#meniscus) while aspirating, dispensing, or mixing in a Python protocol. 
+
 ### Non-blocking commands
 
 Some module commands that take a long time to complete (such as heating from ambient temperature to a high temperature) can be run in a *non-blocking* manner. This lets your protocol save time by continuing on to other pipetting tasks instead of waiting for the command to complete. Non-blocking commands are currently supported on the [Heater-Shaker Module](https://docs.opentrons.com/v2/modules/heater_shaker.html#non-blocking-commands).
diff --git a/docs/flex/docs/system-description/pipettes.md b/docs/flex/docs/system-description/pipettes.md
@@ -264,7 +264,7 @@ A photointerruptor switch detects the position of the pipette's tip ejector mech
 
 ### Pressure sensors
 
-Flex pipettes use internal pressure sensors to detect liquid in well plates, reservoirs, and tubes. Liquid detection takes place as a pipette approaches the surface of a liquid. Sensors in the pipettes detect pressure changes relative to ambient pressure. A particular change in pressure tells the robot that liquid is present in a well and the pipette tip is in contact with the liquid's surface.
+Flex pipettes use internal pressure sensors to detect liquid in well plates, reservoirs, and tubes. Liquid detection takes place as a pipette approaches the surface of a liquid. Sensors in the pipettes detect pressure changes relative to ambient pressure. Particular changes in pressure tell the robot whether liquid is present in a well, the liquid level, and whether the pipette tip is in contact with the liquid's surface.
 
 1-channel pipettes have one pressure sensor. The 8-channel pipette pressure sensors are on channels 1 and 8 (positions A1 and H1). The 96-channel pipette pressure sensors are on channels 1 and 96 (positions A1 and H12). Other channels on multi-channel pipettes do not have sensors and cannot detect liquid.
 
diff --git a/docs/flex/docs/touchscreen/quick-transfer.md b/docs/flex/docs/touchscreen/quick-transfer.md
@@ -42,6 +42,8 @@ If everything is set up correctly, you'll move on to selecting pipettes and tips
 
 Creating a quick transfer involves selecting a pipette and appropriate tips. Quick transfer can use any 1-, 8-, or 96-channel pipette that's attached to the robot. When selecting a pipette tip, try to match the tip to a pipette of the same capacity or larger. For best performance, use the smallest tips that can hold the amount of liquid you need to aspirate.
 
+Beginning with robot software version 8.6.0, you can apply Opentrons-verified liquid class settings in a quick transfer. After choosing your pipette and tips, select the aqueous, viscous, or volatile liquid class to increase pipetting accuracy.
+
 ## Labware
 
 Quick transfer works with most of the labware in the [Opentrons Labware Library](https://labware.opentrons.com/). It omits labware from the source and destination menus when those items are incompatible with the selected pipette. For example, only the 1-channel pipette can aspirate or dispense from tube racks. If you select a multi-channel pipette, quick transfer won't let you choose a tube rack as a source or destination.
@@ -74,10 +76,11 @@ You'll set the amount of liquid to transfer (in μL) after specifying the source
 
 These are available after you name a quick transfer and before you save it. If some settings are familiar to you that's because they're the same as those offered in Protocol Designer. Advanced settings are optional; select any that you need or just save or run the transfer.
 
+If your quick transfer will apply liquid class settings, values for your chosen liquid class are shown for each advanced setting. You can still make changes before moving to the next step. 
+
 | Setting {style="width: 25%;"} | Description |
 |----------|-------------|
 | Aspirate and dispense flow rates | Set how quickly the pipette will aspirate or dispense, in μL/s.|
-| Pipette path           | Choose how the pipette moves between wells. Options include:<br><ul><li>single transfer (1 well to 1 well)</li><li>multi-aspirate (many wells to 1 well)</li><li>multi-dispense (1 well to many wells)</li></ul> |
 | Tip position           | Change where in the well the pipette aspirates or dispenses. By default, the robot positions the tip 1 mm from the bottom center of a well. |
 | Pre-wet tip            | Pre-wet the pipette tip by aspirating and dispensing ⅔ of the tip's maximum volume. |
 | Mix                    | Aspirate and dispense repeatedly from a single location. Used to mix the contents of a well together. |
