Page 29 - 2024-Vol20-Issue2

25 | Bresam & Al-Mumen

TABLE I.
SUMMARY OF EMA ACTUATION TECHNOLOGIES

Year Reference Shape of Number of Actuation Equipment Material of Magnet Speed of
Microrobot Coils Microrobot
2009 [30]
2009 [40] rectangular 5 pair square neodymium-iron-boron (mm/s)
cylindrical 3 pair 2 helmholtz neodymium 8
2010 [37] and 1Maxwell -
spherical 5 pair 3 helmholtz and neodymium
2010 [32] 2 Maxwell -
elliptical 8 coils cylindrical neodymium-iron-boron
2010 [35] -
cylinder 2 pairs octomag neodymium
2011 [38] 2 helmholtz and 0.5
2014 [29] spiral 4 pair neodymium
2015 [50] cylinder 8 coils 2 Maxwell - -
hybrid 3 pair 3 helmholtz and -
2017 [27] neodymium 4.74
spiral 5 pairs 1 Maxwell
2019 [34] cylinder - -
capsule 5 pairs
2020 [39] 3helmholtz neodymium -
2020 [12] cone 8 coils 1 helmholtz,
2020 [45] spherical 8 coils 1 Maxwell and neodymium-iron-boron -
3 coils neodymium-iron-boron -
disk 3 saddle 2.5
1 helmholtz, neodymium
1 Maxwell,

3 saddle
rectangular octomag

circular coils
identical circular coils

promising actuation approach for biomedical applications. Ev- tively accomplished under optical control [57]. The ability to
ery magnetic device or object will interact with the magnetic control mobile micro devices with light has several inherent
field. The frequency, magnitude, and direction of the magnetic limitations. Light-based systems are mostly restricted to two-
field can be varied to allow different robots to modify their dimensional control, whereas magnetic and acoustic fields can
posture, speed, and direction. It is possible to consider the control micro-objects in three dimensions. The workspace
multi-degree of freedom of a robot due to the fact that robots must also be optically accessible for control, and the micro
with varied structures will react to the magnetic field very devices must move in a clear, transparent medium. Therefore,
differently. Table I shows the summary of EMA actuation medicinal applications in bodily tissues are very challenging.
technologies with different numbers, and shapes of coils. Fig. 4 shows the optic actuation of the microrobot.

B. Optic Actuation C. Acoustic Actuation
A microrobot that has used optical micromanipulation tech- Another attractive and practical method for wirelessly acti-
nology is known as an optical microrobot [54]. The direction, vating and functionalizing microrobots is acoustic actuation.
polarization, wavelength, and intensity of the incident light Acoustic vibration fields have been used to generate vibra-
may all be accurately controlled through the use of light actu-
ation, which is also exhibiting great promise as a method of Fig. 4. Optic actuation of the microrobot
propulsion [55]. A novel micro-rocket robot has been devel-
oped that includes an all-optic drive and an imaging system
that can precisely actuate and monitor it at the microscale [56].
Also, phototaxis was used to develop a mechanism for steer-
ing swimming cells. The approach used a changing light
signal, and their motions along set trajectories were effec-