Electrophysiology: Piezos Enable Faster Solution Switching

Electrophysiological studies require fast motions of a double-bore (theta-glass) pipette across cell membranes.

With a cell held in a patch clamp and monitored electrical-ly, one bore of the pipette flows a buffer solution, while the other carries a drug or other chemical. By quickly sweeping the pipette so one bore or the other suffuses the cell, its electrophysiological response can be correlated to the chemical environment.

Piezos are ideal for fast switching, as they offer electromagnetic quietness, good repeatability, high relia-bility and fast speeds. However, fast acceleration can mean recoil forces excite vibration in the pipette and both piezo and stepper actuators have suffered from these in the past. These cause unwanted, repetitive solution switching for many milliseconds.

Enabling fast sweeps without vibration

Now Siskiyou and PI have collaborated on an approach which can eliminate unwanted switching, yielding crisp, artifact-free data. Siskiyou’s MXPZT-300 integrates PI’s high-speed flexure guided piezo nanopositioner with a convenient, stable coarse positioning stack. Patented Input Shaping® vibration-canceling technology nullifies the repetitive switching. Piezo movement is controlled by input from popular recording amplifier equipment. The MXPZT-300 controller incorporates all electronics and provides connectivity to popular electrophysiological equipment from respected manufacturers.