Digital Peristaltic Pump

The starting point is a list of performance parameters, such as flow rate, pressure, total volume to be pumped, chemical and physical properties of the liquids (or even gases), pressure dependency of the flow rate, flow variations ("ripple"), temperature of the liquid, and many others. If you do not define what you need, it is impossible to say, what's the best. Different pumps have very different properties. In syringe pumps you may use plastic, glass or metal syringes, which also are quite different in performance and cost.

I use syringe pumps to control the flow rate inside microfluidic channels, they seem pretty accurate (I use CETONI's neMESYS low pressure module) and induce a very stable flow rate. However, I found it always inconvenient when I had to refill the syringe halfway through the experiment, and since I use glass syringe, they are prone to leakage or malfunction if not handled probably and they are expensive.

In my application, the pressure and flow rate consistency are the most crucial features. But if could design a pumping system that is accurate, stable, has a better refill mechanism and for a realizable price, I'm sure it would be a great achievement.

Ahmed Albagdady Thank you, that was very useful, a few more questions to add.

How many experiments do you perform on an average annually ?

What price range would be a ideal according to you for a glass syringe ?

Nisarga Venkataswamy Glad to be of help. when I am in the experimentation phase, I use it almost daily with about 5 hours per session, so I do a lot of refilling. The SETonic syringes I use are quite good but if you tighten the connector a little more it would disconnect and if it is loosened it will leak, so they are a bit sensitive and require a trained hand to use them.

The syringe cost about 75 euros but it is reusable if you clean it probably.

I may be an option to use plastic syringes in syringe pumps. Glass syringes break easily and are much more expensive.

Michael G. Weller It depends on the pressure you are working on. Plastic syringe cannot withstand higher pressure values.

Hi,

from a little bit different perspective: you can make your own pumps for fraction of the price. The schematics and instructions are available for free at Droplet Kitchen.

https://github.com/DropletKitchen/pumpsn17

(hmm...sounds like an ad, but it is not)

Btw. I use nemezys from cetoni. Nice ones, but quite expensive. And I would stick to glass syringes, plastics tend to bend from my experience.

Hi,

I have been working on monodisperse droplet generation for 4 years. Since the droplet monodispersity is influenced by the pressure/flow rate fluctuations, the fluctuations due to the pump plays a significant role. Therefore, I prefer to use pressure pump than syringe pump which has higher fluctuations due to its mechanism. I know using compliance effect (using plastic syringe or flexible tubing) damps flow rate fluctuations in syringe pump, but then the response time would be annoying. Nevertheless, in droplet generation the syringe pump is beneficial when we want to make droplets in a specific flow rate of the fluids.

Adam Opalski Thank you Sounds interesting !! will definitely look into it ! :)

Late answer, but might maybe still help you:

I totally agree with Ali Kalantarifard . In our design, we use a Mitos Dolomite p-pump with flow rate sensors to ensure a high-quality pulsation-free flow. However, in this case you have to take care of the additional measurement devices and always keep your flow-rate calibration up-to-date.

Furthermore, I would say it depends on the aim you are trying to reach. There are many works that figure out a difference between pressure-driven and volume-flow driven operation of your chip. For volume-flow driven operation, a syringe-pump is the best possibility in my point of view.

Since I was working a lot with PIV-particles, I always wished for a syringe pump that could prevent sedimentation of the particles at very low flow rates. Also a tempered syringe like in droplet-volume-tensiometers would be a great advantage since it helps to stabilize the particle suspension.