Microneedling, Part 2: Comparison of Motor and Drive Types
From our series: Equipment-based cosmetics
Microneedling is not just a short-lived beauty trend. Microneedling is above all an innovative treatment method with a great deal of potential – provided the technology and application are correct.
In three articles we present the differences between the various offerings:
• Perforation patterns of the respective needle head geometry
• Motor and drive concept: effects on perforation (this page)
• Operating speed and effects on the perforation pattern
The diverse microneedling devices and needle modules differ in essential details: technology, needle head geometry, working direction and operating speed
In this article we address:
Comparison of motor and drive types
Currently there are two connection systems in microneedling: the rigid connection between motor and needle module and a spring-mounted connection between motor and needle head.
Fundamentally, from a technical perspective the question arises: Which system is better suited for an exact and clean perforation?
• A direct connection means that the needle module is firmly and rigidly connected to the motor. Advantage: With full motor/drive power the needles can penetrate the skin and be withdrawn again without delay (see: motor with fixed/rigid connection
• A spring-mounted needle head does not have a rigid but a spring-mounted connection, so that the motor’s power is not fully available. When the needle is to penetrate the skin, the motor works against the spring. This causes the spring to tension, so motor power is lost when the needle is to penetrate the skin quickly and cleanly. When withdrawing the needle the tensioned spring is released and the needles are retracted.
Linear needler: direct force transmission from motor to the needle module
Round-head needler with indirect, spring-mounted force transmission between motor and needle round head
Technical notes
How, at a frequency of 90-150 Hz, i.e. 90-150 needle insertions and withdrawals per second, can a spring mechanism that reacts sluggishly (law of inertia) operate quickly and precisely with a consistently identical needle penetration depth?
A rigid and therefore fixed connection between motor and needle head represents the technically optimal solution, because repeatability is greater and at the same time 100 % of motor power can always be transferred to the needle module.
The more needles there are in a needle module (9-40), the more force the motor must exert to allow the needles to penetrate the skin. The more needles, the greater the fakir effect. This means: motor power (force) must also be taken into account to prevent a fakir effect.
Fakir effect
Very densely placed needles from a certain number and distance from one another produce the fakir effect. This means: the needles no longer penetrate the skin but first press on the skin. With further pressure build-up the skin then tears – if motor power is too low.
Fakir effect: Which needle module penetrates the skin more easily?
Note on the spring mechanism
With a spring mechanism the needles cannot be inserted into or withdrawn from the skin evenly with full power. This carries the risk of increased tear injuries, because the needles are still in the skin while the needler is already being moved further across the treatment area – often at far too high an operating speed.
Motor Power
The force with which a motor drives the varying number of needles against the skin barrier to penetrate the skin is crucial for a clean and precise perforation and also for the retraction of the needles from the skin.
2. Microneedling – Comparison of Motor and Drive Concepts
Currently there are two connection systems: the fixed/rigid connection between motor and needle module and a spring-mounted connection between motor and needle head. From a technical perspective the question arises as to which system is better suited for an exact and clean perforation?
• A direct connection means that the needle module is firmly and rigidly connected to the motor. Advantage: with full motor/drive power the needles can penetrate the skin and be retracted again without delay – see motor with fixed/rigid connection
• A spring-mounted needle head does not have a rigid but a spring-mounted connection, so that the motor power is not fully available. When the needle is to penetrate the skin, the motor works against the spring, which is thereby tensioned; thus motor power is lost when the needle is to penetrate the skin quickly and cleanly. When retracting the needle, the tensioned spring is released and the needles are returned.
Linear Needler – direct force transmission from motor to needle module
Round-head Needler with indirect, spring-mounted force transmission between motor and needle round head
Technical remarks: How can a spring mechanism that reacts sluggishly (law of inertia) work quickly and precisely with always the same needle penetration depth at a frequency of 90-150 Hz, i.e. 90-150 needle insertions and retractions per second? A rigid and thus fixed connection between motor and needle head represents the technically optimal solution because the repeatability is greater and at the same time 100% of the motor power can always be transmitted to the needle module. The more needles there are in a needle module (9-40), the more force the motor must exert to allow the needles to penetrate the skin. The more needles, the greater the fakir effect – this means that the power (force) of the motor is also important and must be taken into account to prevent a fakir effect.
Fakir effect – which needle module, linear or round head, penetrates the skin more easily?
Note on the spring mechanism: With a spring mechanism the needles cannot be inserted into the skin and/or withdrawn with full power and uniformity. This carries the risk of increased tear injuries because the needles are still in the skin while the needler is already being moved further across the treatment area – often still at far too high a working speed.
Motor Power
The force with which a motor drives the varying large number of needles against the skin barrier to penetrate the skin is crucial for a clean and precise perforation and also for the retraction of the needles from the skin.